Merging to release-5.8: [TT-14829] Added External OAuth Deprecated mark in godoc (#7050)

[TT-14829] Added External OAuth Deprecated mark in godoc (#7050)

### **User description**
<details open>
<summary><a href="https://tyktech.atlassian.net/browse/TT-14829"
title="TT-14829" target="_blank">TT-14829</a></summary>
  <br />
  <table>
    <tr>
      <th>Summary</th>
<td>Add deprecated go doc to External Oauth field in API Definition</td>
    </tr>
    <tr>
      <th>Type</th>
      <td>
<img alt="Bug"
src="https://tyktech.atlassian.net/rest/api/2/universal_avatar/view/type/issuetype/avatar/10303?size=medium"
/>
        Bug
      </td>
    </tr>
    <tr>
      <th>Status</th>
      <td>In Dev</td>
    </tr>
    <tr>
      <th>Points</th>
      <td>N/A</td>
    </tr>
    <tr>
      <th>Labels</th>
      <td>-</td>
    </tr>
  </table>
</details>
<!--
  do not remove this marker as it will break jira-lint's functionality.
  added_by_jira_lint
-->

---

<!-- Provide a general summary of your changes in the Title above -->

## Description

<!-- Describe your changes in detail -->

## Related Issue

<!-- This project only accepts pull requests related to open issues. -->
<!-- If suggesting a new feature or change, please discuss it in an
issue first. -->
<!-- If fixing a bug, there should be an issue describing it with steps
to reproduce. -->
<!-- OSS: Please link to the issue here. Tyk: please create/link the
JIRA ticket. -->

## Motivation and Context

<!-- Why is this change required? What problem does it solve? -->

## How This Has Been Tested

<!-- Please describe in detail how you tested your changes -->
<!-- Include details of your testing environment, and the tests -->
<!-- you ran to see how your change affects other areas of the code,
etc. -->
<!-- This information is helpful for reviewers and QA. -->

## Screenshots (if appropriate)

## Types of changes

<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->

- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Refactoring or add test (improvements in base code or adds test
coverage to functionality)

## Checklist

<!-- Go over all the following points, and put an `x` in all the boxes
that apply -->
<!-- If there are no documentation updates required, mark the item as
checked. -->
<!-- Raise up any additional concerns not covered by the checklist. -->

- [ ] I ensured that the documentation is up to date
- [ ] I explained why this PR updates go.mod in detail with reasoning
why it's required
- [ ] I would like a code coverage CI quality gate exception and have
explained why


___

### **PR Type**
documentation


___

### **Description**
- Added deprecation notice to `ExternalOAuthType` constant.

- Updated GoDoc for `ExternalOAuth` to indicate deprecation.

- Provided migration guidance to use JWT instead.

- Linked to documentation for further details.


___



### **Changes walkthrough** 📝
<table><thead><tr><th></th><th align="left">Relevant
files</th></tr></thead><tbody><tr><td><strong>Documentation</strong></td><td><table>
<tr>
  <td>
    <details>
<summary><strong>api_definitions.go</strong><dd><code>Add deprecation
notice to ExternalOAuthType constant</code>&nbsp; &nbsp; &nbsp; &nbsp;
&nbsp; </dd></summary>
<hr>

apidef/api_definitions.go

<li>Added deprecation GoDoc to <code>ExternalOAuthType</code>
constant.<br> <li> Explained deprecation and recommended JWT as
alternative.<br> <li> Linked to relevant documentation for migration.


</details>


  </td>
<td><a
href="https://github.com/TykTechnologies/tyk/pull/7050/files#diff-9961ccc89a48d32db5b47ba3006315ef52f6e5007fb4b09f8c5d6d299c669d67">+11/-6</a>&nbsp;
&nbsp; </td>

</tr>

<tr>
  <td>
    <details>
<summary><strong>security.go</strong><dd><code>Add deprecation notice to
ExternalOAuth struct documentation</code></dd></summary>
<hr>

apidef/oas/security.go

<li>Added deprecation GoDoc to <code>ExternalOAuth</code> struct.<br>
<li> Provided migration advice and documentation link.


</details>


  </td>
<td><a
href="https://github.com/TykTechnologies/tyk/pull/7050/files#diff-15e7d47137452ca4f3f6139aa8c007cdb426152c41846f712f8bf5dfb607afcc">+1/-0</a>&nbsp;
&nbsp; &nbsp; </td>

</tr>
</table></td></tr></tr></tbody></table>

___

> <details> <summary> Need help?</summary><li>Type <code>/help how to
...</code> in the comments thread for any questions about PR-Agent
usage.</li><li>Check out the <a
href="https://qodo-merge-docs.qodo.ai/usage-guide/">documentation</a>
for more information.</li></details>

Author: buger

apidef/api_definitions.go

@@ -111,14 +111,23 @@ const (
 	DefaultAPIVersionKey = "x-api-version"
 	HeaderBaseAPIID      = "x-tyk-base-api-id"
 
-	AuthTokenType     = "authToken"
-	JWTType           = "jwt"
-	HMACType          = "hmac"
-	BasicType         = "basic"
-	CoprocessType     = "coprocess"
-	OAuthType         = "oauth"
+	AuthTokenType = "authToken"
+	JWTType       = "jwt"
+	HMACType      = "hmac"
+	BasicType     = "basic"
+	CoprocessType = "coprocess"
+	OAuthType     = "oauth"
+	// ExternalOAuthType holds configuration for an external OAuth provider.
+	// Deprecated: ExternalOAuth support has been deprecated from 5.7.0.
+	// To avoid any disruptions, we recommend that you use JSON Web Token (JWT) instead,
+	// as explained in https://tyk.io/docs/basic-config-and-security/security/authentication-authorization/ext-oauth-middleware/.
 	ExternalOAuthType = "externalOAuth"
-	OIDCType          = "oidc"
+	// OIDCType holds configuration for OpenID Connect.
+	// Deprecated: OIDC support has been deprecated from 5.7.0.
+	// To avoid any disruptions, we recommend that you use JSON Web Token (JWT) instead,
+	// as explained in https://tyk.io/docs/api-management/client-authentication/#integrate-with-openid-connect-deprecated.
+
+	OIDCType = "oidc"
 
 	// OAuthAuthorizationTypeClientCredentials is the authorization type for client credentials flow.
 	OAuthAuthorizationTypeClientCredentials = "clientCredentials"

apidef/oas/security.go

@@ -634,7 +634,7 @@ func (c *IntrospectionCache) ExtractTo(cache *apidef.IntrospectionCache) {
 }
 
 // ExternalOAuth holds configuration for an external OAuth provider.
-// ExternalOAuth support will be deprecated starting from 5.7.0.
+// Deprecated: ExternalOAuth support has been deprecated from 5.7.0.
 // To avoid any disruptions, we recommend that you use JSON Web Token (JWT) instead,
 // as explained in https://tyk.io/docs/basic-config-and-security/security/authentication-authorization/ext-oauth-middleware/.
 type ExternalOAuth struct {
@@ -853,7 +853,10 @@ func resetSecuritySchemes(api *apidef.APIDefinition) {
 	// External OAuth
 	api.ExternalOAuth = apidef.ExternalOAuth{}
 
-	// OIDC
+	// OIDC holds configuration for OpenID Connect.
+	// Deprecated: OIDC support has been deprecated from 5.7.0.
+	// To avoid any disruptions, we recommend that you use JSON Web Token (JWT) instead,
+	// as explained in https://tyk.io/docs/api-management/client-authentication/#integrate-with-openid-connect-deprecated.
 	api.UseOpenID = false
 	api.Scopes.OIDC = apidef.ScopeClaim{}
 	api.OpenIDOptions = apidef.OpenIDOptions{}