fix: allow distro definitition override

[hanthor]

Fixes #904

This accepts --override-distro-def=fedora-40.yaml to set the manifest. I'm not sure if this is ideal or if it would better to have it do into the the distrodef function like normal and allow for fuzzy match

[hanthor]

	// use lorax-templates-rhel if the source distro is not Fedora with the exception of Fedora ELN
	img.UseRHELLoraxTemplates =
		c.SourceInfo.OSRelease.ID != "fedora" || c.SourceInfo.OSRelease.VersionID == "eln"

This is problematic for me https://github.com/hanthor/bootc-image-builder/blob/725b710052510c35e15ff09ff571b5a8e3be83af/bib/cmd/bootc-image-builder/image.go#L505-L508

[supakeen]

	// use lorax-templates-rhel if the source distro is not Fedora with the exception of Fedora ELN
	img.UseRHELLoraxTemplates =
		c.SourceInfo.OSRelease.ID != "fedora" || c.SourceInfo.OSRelease.VersionID == "eln"

This is problematic for me https://github.com/hanthor/bootc-image-builder/blob/725b710052510c35e15ff09ff571b5a8e3be83af/bib/cmd/bootc-image-builder/image.go#L505-L508

This logic can likely be inverted to always use -generic unless it's RHEL, Alma Linux, or ELN. Thoughts? cc @mvo5 / @ondrejbudai?

[Venefilyn]

So with distros that are based on a specific system there is always ID_LIKE. Could that be the primary thing to look for with ID as a backup, or are there edge-cases here that I do not know of?

Example:

NAME="Bazzite"
VERSION="42.20250501.0 (Silverblue)"
RELEASE_TYPE=stable
ID=bazzite
ID_LIKE="fedora"
VERSION_ID=42
VERSION_CODENAME="Holographic"
PLATFORM_ID="platform:f42"
PRETTY_NAME="Bazzite 42 (FROM Fedora Silverblue)"

[hanthor]

ID_LIKE can have multiple entries in it I think. Like Centos has rhel and fedora

[mvo5]

Fwiw, we inverted the #907

	// use lorax-templates-rhel if the source distro is not Fedora with the exception of Fedora ELN
	img.UseRHELLoraxTemplates =
		c.SourceInfo.OSRelease.ID != "fedora" || c.SourceInfo.OSRelease.VersionID == "eln"

This is problematic for me https://github.com/hanthor/bootc-image-builder/blob/725b710052510c35e15ff09ff571b5a8e3be83af/bib/cmd/bootc-image-builder/image.go#L505-L508

This part got (hopefully) fixed with #907 - is there more that is causing issues for you? FTR I'm fine with a way to override the detection, mostly wondering if there are more things we should/could fix "automatically"

[hanthor]

We either need to ignore edits to os-relase and find a more hardcoded way to detect the distro or allow for overrides/have helpful text for the user when the manifest isn't found guiding them to just override to fedora or centos etc.