[Feature flag] Cleanup `allow_git_http_fetch_writes`

Summary

This issue is to clean up the allow_git_http_fetch_writes feature flag. This FF was not enabled by default since it was created as a safety net to enable the project_daily_statistics per project actor. Since we disable the disable_git_http_fetch_writes FF in production, all projects have the statistics enabled, which means that the allow_git_http_fetch_writes FF is not needed anymore.

Owners

• Team: source_code_management
• Most appropriate slack channel to reach out to: #g_create_source-code-be
• Best individual to reach out to: @jtapiab
• PM: @mcbabin

Expectations

What might happen if this goes wrong?

There should not be any regression. This FF was not enabled, and we did not use it.

Cleaning up the feature flag

• Specify in the issue description if this feature will be removed completely or will be productized as part of the Feature Flag cleanup
• Create a merge request to remove allow_git_http_fetch_writes feature flag. Ask for review and merge it.
  • Remove all references to the feature flag from the codebase.
  • Remove the YAML definitions for the feature from the repository.
  • Create a changelog entry.
• Ensure that the cleanup MR has been deployed to both production and canary. If the merge request was deployed before the code cutoff, the feature can be officially announced in a release blog post.
  • /chatops run auto_deploy status 4642f688
• Close the feature issue to indicate the feature will be released in the current milestone.
• If not already done, clean up the feature flag from all environments by running these chatops command in #production channel: /chatops run feature delete allow_git_http_fetch_writes --dev --pre --staging --staging-ref --production
• Close this rollout issue.