mesa: remove dummy transitional packages

[ericonr]

Related to #20861 as well. I'm making this PR also to open the discussion about it. Last mesa reorganization was made by @st3r4g (from what I could gather looking at PRs), and they suggested the removal of those packages.

Perhaps the only packages that could be advantageous to keep would be those that have dependencies beyond mesa-dri. Like the Intel, Nouveau and ATI ones.

[st3r4g]

Well this is not what I meant in #20861. I suggested to purge the obsolete mesa-*-dri-dbg (debug symbols) binary packages (only repoadmins can do this), not the dummy templates, that are still required for people who have not updated yet their system after the reorganization. It's been only ~5 months, maybe it's better to wait a bit more.

Perhaps the only packages that could be advantageous to keep would be those that have dependencies beyond mesa-dri. Like the Intel, Nouveau and ATI ones.

I made them like that because e.g. mesa-intel-dri had vulkan_intel inside, so that users would get the equivalent new packages after the reorganization.

[ericonr]

@st3r4g shit, sorry. I might have jumped the gun a bit. I had thought about the update path for people still using the old packages, but hadn't realized it had been changed so little time ago. I should probably close it then.

[st3r4g]

no problem