Remove `determine_blank_ref_based_on_gitaly_object_format` feature flag
requested to merge remove-determine_blank_ref_based_on_gitaly_object_format-feature-flag into master
What does this MR do and why?
This merge request removes the determine_blank_ref_based_on_gitaly_object_format feature flag to ensure we always determine a repository's blank sha reference based on gitaly's ObjectFormatRequest which determines a repository's object format (i.e. whether it's sha1 or sha256).
MR acceptance checklist
I have evaluated this MR against the MR acceptance checklist.