Remove old CI sections (#14149)

These no longer applies.

Author: armenzg

develop-docs/development-infrastructure/continuous-integration.mdx

@@ -23,21 +23,3 @@ We use Google Cloud Build to build our Docker containers. Every single commit (i
 ## CI workflow for testing changes with getsentry
 
 See [Workflow](/development/workflow/).
-
-## Troubleshooting CI
-
-You might also be interested in <Link to="/development/environment/#troubleshooting">troubleshooting the dev environment</Link>.
-
----
-
-**Problem:**
-
-When pushing your build to staging and it fails the `Ensure test image` step on Travis.
-
-**Solution:**
-
-You probably forgot to push your branch on Sentry to GitHub.
-
-## Old Systems
-
-For historical reference, we used to use Travis and Percy which have been replaced by GitHub actions and [a GitHub action](https://github.com/getsentry/action-visual-snapshot) respectively.