kirkstone: Backport from scarthgap

[adalessandro]

Yocto Kirkstone is LTS (until Apr. 2026) but due to its dependency on meta-clang [0], the chromium version is freezed at 120.0.6099.224.

Issue OSSystems/meta-browser#842 keeps track of ongoing efforts on updating Chromium in Kirkstone.

See comment OSSystems/meta-browser#716 (comment):

[...] Note that clang 16 is the bare minimum we need to build Chromium, but that might change again (or might have changed already since the last time we built kirkstone). Thus, having clang 17 or 18 (scarthgap uses 18) would be even better.

meta-clang scarthgap currently provides clang 18.1.6, so backporting from it seems to be the best path here.

[0] OSSystems/meta-browser#716

[adalessandro]

Pushed WIP branch backporting from scarthgap: https://github.com/adalessandro/meta-clang/tree/wip/adalessandro/kirkstone-backport-scarthgap
Building clang-native recipe, passed.

[adalessandro]

@kraj is there some sort of pipeline to build/test different configurations?

[adalessandro]

Closing in favor of #1040