feat: add Packit integration

[ptoscano]

Add a basic configuration for building PRs using Packit, using EL 8/9 and supported Fedora's.

The actions are needed to do the "make srpm" way manually, which is what Copr does.

Also drop the GitHub Actions for building packages manually, as Packit covers it now (and even for more distros).

[packit-as-a-service]

Failed to load packit config file:

Cannot parse package config. ValidationError({'jobs': {0: {'packages': defaultdict(<class 'dict'>, {'yggdrasil': {'value': {'targets': ["Expected 'list[str]' or 'dict[str,dict]', got [{'centos-stream-8': {'additional_repos': ['https://download.copr.fedorainfracloud.org/results/%40yggdrasil/latest/centos-stream-$releasever-x86_64/']}}, {'centos-stream-9': {'additional_repos': ['https://download.copr.fedorainfracloud.org/results/%40yggdrasil/latest/centos-stream-$releasever-x86_64/']}}, {'fedora-all': {'additional_repos': ['https://download.copr.fedorainfracloud.org/results/%40yggdrasil/latest/fedora-$releasever-x86_64/']}}, {'rhel-8': {'additional_repos': ['https://download.copr.fedorainfracloud.org/results/%40yggdrasil/latest/rhel-$releasever-x86_64/']}}, {'rhel-9': {'additional_repos': ['https://download.copr.fedorainfracloud.org/results/%40yggdrasil/latest/rhel-$releasever-x86_64/']}}] (type <class 'list'>)."]}}})}}})

For more info, please check out the documentation or contact the Packit team.

[ptoscano]

/packit build

[ahitacat]

/packit build

[ahitacat]

LGTM