fix: skip running tests on changes in validate-deploy-docs.yaml (#416)

### Description
- Since we now have a new validate-deploy-docs.yaml workflow for
documentation, we are including it in the list of files considered as
documentation-only changes. This ensures that test cases will not be
triggered when only documentation workflows are modified.

### Checklist

- [ ] `README.md` has been updated or is not required
- [ ] push trigger tests
- [ ] manual release test
- [ ] automated releases test
- [ ] pull request trigger tests
- [ ] schedule trigger tests
- [ ] workflow errors/warnings reviewed and addressed

### Testing done for test addon repo

https://github.com/splunk/test-addonfactory-repo/actions/runs/15874408448/job/44758591172?pr=349

Author: siddharth-khatsuriya

.github/workflows/reusable-build-test-release.yml

@@ -133,15 +133,15 @@ jobs:
       - name: Fetch all refs
         run: git fetch --prune --unshallow
 
-      - name: Check if the changes are only in docs/*, mkdocs.yml, or .github/workflows/docs.yml
+      - name: Check if the changes are only in docs/*, mkdocs.yml or .github/workflows/validate-deploy-docs.yaml
         id: check
         run: |
           set -o xtrace
           # List all files modified in the commit or PR
           changed_files=$(git diff --name-only --diff-filter=ACMRT ${{ github.event.pull_request.base.sha }} ${{ github.sha }})
 
-          # Check if any of the changed files are not in docs/*, mkdocs.yml, or .github/workflows/docs.yml
-          if echo "$changed_files" | grep -vqE '^(docs/|mkdocs.yml|.github/workflows/docs.yml)'; then
+          # Check if any of the changed files are not in docs/*, mkdocs.yml, or .github/workflows/validate-deploy-docs.yaml
+          if echo "$changed_files" | grep -vqE '^(docs/|mkdocs.yml|.github/workflows/validate-deploy-docs.yaml)'; then
             echo "docs-only=false" >> "$GITHUB_OUTPUT"
           else
             echo "Only documentation changes found."