feat: standardize versioning across OSTree and os-release

[antheas]

Chain PR with #1439

This PR swaps the tag generator with 2 parts, one that generates a primary tag that propagates throughout the containerfile, and one that generates a bunch of tags that are pushed to GHCR.

Primary Tag

The first part generates a unique tag and pretty version for the image that gets propagated to the Containerfile.

Examples (pretty, tag):
- Stable (v3.6, F40.240603) and stable-v3.6-40.240603
- Testing (v3.6, F40.240603) and testing-v3.6-40.240603
- Unstable (#asfcd32, F40.240603) and unstable-asfcd32
- PR (13435, F40) and pr-40-13435

In this case, the upstream kinoite tag is used, indicating the package versions that make up the OS. This disambiguates bazzite tags and kinoite tags, as they use the same primary tag.

Currently, a timestamp tag generated on the moment is used, which is confusing to users.

Where applicable (meaning not unstable/PRs), it also contains the Bazzite version, which can be clearly communicated to users and used for marketing purposes.

The pretty release is then placed in os-release, under BOOTLOADER_NAME, which we can make OSTree use for grub.

After building the image, this tag is fed through rechunk, which checks GHCR for the same tag and if it exists appends .1, .2, .3, etc. Then, rechunk attaches this to the container label, which is shown on rpm-ostree status. Unfortunately, the suffix will be absent from os-release and grub, since the image is already built.

Secondary tags

Along with the unique version produced by rechunk, the secondary part of this action attaches a variety of tags to the uploaded image, including Bazzite version, Kinoite version, and Fedora version. The images are then tagged with podman and uploaded to GHCR with the existing action.

Important

#1439 needs to be merged first and the version structure needs a bit of polish.