Rewrite IsRebaseInProgress in go
This is ruby-endpoint has one of the highest requests/second. And as the check is literaly File.exist?
followed by File.mtime
and potentially a File.rm_rf
this should be rewritten in Go.
https://gitlab.com/gitlab-org/gitaly/blob/91659758bbc621449dbd3fa222c5cffcc5d0e171/ruby/vendor/gitlab_git/lib/gitlab/git/repository.rb#L1283-1291
https://gitlab.com/gitlab-org/gitaly/blob/91659758bbc621449dbd3fa222c5cffcc5d0e171/ruby/vendor/gitlab_git/lib/gitlab/git/repository.rb#L1658-1660