1. Fix incorrect `MentionCount` (actually it seems to be deadcode,
affects nothing)
2. Remove fallback sha1 support for time limit token
3. Use route middleware `reqRepoActionsWriter` for `ArtifactsDeleteView`
4. Use clearer message "Failed to authenticate user" instead of "Verify"
when auth fails
5. `tests/integration/benchmarks_test.go` is not quite right, actually
it is never used, so delete it.
6. Remove or update TODO comments
5dddcc1773