Revert "Merge branch 'rodrigo/enable_github_import_lock_user_finder_ff' into 'master'"

This reverts merge request !143118

https://gitlab.com/gitlab-org/gitlab/-/merge_requests/143285

config/feature_flags/development/github_import_lock_user_finder.yml

@@ -5,4 +5,4 @@ rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/438336
 milestone: '16.9'
 type: development
 group: group::import and integrate
-default_enabled: true
+default_enabled: false