Remove "argsOverride" from linux kernel

[layus]

Motivation for this change

It is a bit strange to use these argsOverride attribute because it does not play well with the .override mechanism. The current situation is also inconsistent since #31596 was merged.

Things done

This patch unifies the syntax for all the kernels by removing the argsOverride support and merging the input args after the default values, making everything overridable.
A deprecation warning was also introduced for users relying on that feature.

• Tested that all the derivations are strictly unchanged by this patch.
• Fits CONTRIBUTING.md.

[layus]

@teto @globin for review :-)

[teto]

Depreciation warning is cool.
I don't have much experience regarding the kernel implementation aka why argsOverride was introduce in the first place but being able to use the usual 'override' seems like the way to go

[teto]

can we label this as kernel/merge once rebased ? its is useful

[teto]

rebase ?

[layus]

Retrospectively, I think this is a bad idea. there is no reason to merge the full "args" attrset into the final derivation. We should really make buildLinux overridable.

[teto]

Isn't it already the case?
buildLinux = makeOverridable (callPackage ../os-specific/linux/kernel/generic.nix {});
argsOverride doesn't seem to be used anywhere in nixpkgs. I believe you could even remove the
args // rec {. Seems in line with the recent kernel building improvements.

EDIT: Note the usecase for introducing argsOverride should be adressed too by #31610

[matthewbauer]

merge conflict