Merge branch 'docs/52918-shared-runners-still-showing-in-list-projects-runner-when-shared-runners-disabled-for-project' into 'master'

Fix documentation for list runners

Closes #52918

See merge request gitlab-org/gitlab-ce!22490

Author: axilleas

doc/api/runners.md

@@ -340,8 +340,7 @@ Example response:
 ## List project's runners
 
 List all runners (specific and shared) available in the project. Shared runners
-are listed if at least one shared runner is defined **and** shared runners
-usage is enabled in the project's settings.
+are listed if at least one shared runner is defined.
 
 ```
 GET /projects/:id/runners