Merge branch 'tristan-dkey-api' into 'master'

Docs: clarify deploy keys api availability

See merge request gitlab-org/gitlab!30202

doc/api/deploy_keys.md

@@ -2,7 +2,7 @@
 
 ## List all deploy keys
 
-Get a list of all deploy keys across all projects of the GitLab instance. This endpoint requires admin access.
+Get a list of all deploy keys across all projects of the GitLab instance. This endpoint requires admin access and is not available on GitLab.com.
 
 ```plaintext
 GET /deploy_keys