Reset the branch state due to improper import.
RHEL git ref that the branch was reset to
<899941f60d3248385d8ddecab2889679fb1b1032>.
Summary of the updates:
* `.gitignore`
Restore the looser rules for matching.
* `.gitlab/merge_request_templates/default.md`
Merge Request template file is picked up only from the main branch.
* `gating.yaml`
We don't need the file for this branch.
* `ruby.rpmlintrc`
Was never present for the Ruby 2.7 module.
* `*.patch`
Delete patches wrongly imported from another repository.
* Leave out the ruby.spec changelog changes.
GitBZ check complains when those lines are changed.
Related: rhbz#2149262
