Merge branch '223789-enable-default-branch-main-feature-flag' into 'master'

Set the git default branch to "main"

See merge request gitlab-org/gitlab!62467

config/feature_flags/development/main_branch_over_master.yml

@@ -5,4 +5,4 @@ rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/329190
 milestone: '13.12'
 type: development
 group: group::source code
-default_enabled: false
+default_enabled: true