chore: Add packit service configuration

[Tiboris]

This commit is enabling packit service for the mrack project. see: https://packit.dev/docs/configuration/

To start using Packit we did:

• set up integration on GitHub side and selected free plan
• got approved by mapping FAS identity (tdudlak) to the service via: https://github.com/packit/notifications/issues/482 by linking neoave organization with FAS account
• configured the wanted features via this commit

This commit sets up packit jobs to:

• check build per pull request
• trigger copr build after a release
• create fedora PRs to mrack project with updates
  • rights for packit user for the repo should be added (fedora)
• create koji build per commit merged to fedora's mrack
• create bodhi updates per each successful koji build

This allows us to forget about backporting pathces to Fedora repo and automate release workflow per each supported Fedora release currently not EOL.

Signed-off-by: Tibor Dudlák tdudlak@redhat.com

[Tiboris]

@lbarcziova Thanks for help fixing the config for packit now it nicely green.

[XiyangDong]

Thanks for updating the PR descriptions. With given content I am clear on what feature this PR is implementing. Also the test jobs are passing. Hence approving.