Remove include_lfs_blobs_in_archive feature flag [RUN ALL RSPEC] [RUN AS-IF-FOSS]

This feature flag has been enabled by the default since GitLab 13.5, so it's time to remove it.

Part of #268409 (closed)

config/feature_flags/development/include_lfs_blobs_in_archive.yml

----
-name: include_lfs_blobs_in_archive
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/44116
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/268409
-milestone: '13.5'
-type: development
-group: group::source code
-default_enabled: true