tests linux: do not skip tests depending on kernel <= 6.11

[Marcondiro]

Description

The Linux images used in CI are on 6.11 at the time of writing. Remove the test requiring a kernel <= 6.11 from the skipped ones, addressing the FIXMEs.

Sources

Checklist

• Relevant tests in libc-test/semver have been updated
• No placeholder or unstable values like *LAST or *MAX are
  included (see #3131)
• Tested locally (cd libc-test && cargo test --target mytarget);
  especially relevant for platforms that may not be checked in CI

[tgross35]

I think we're stuck to the host (ubuntu-24.04) kernel versions here since Docker doesn't bring its own kernel. Per https://en.wikipedia.org/wiki/Ubuntu_version_history#Table_of_versions that means 6.8.

[Marcondiro]

Hi, @tgross35, according to CI logs this is the image currently used https://github.com/actions/runner-images/releases/tag/ubuntu24%2F20260111.209

Kernel Version: 6.11.0-1018-azure

[tgross35]

Huh, nice find. Any idea what the issue is then - does the version of the installed headers not match up?

[Marcondiro]

I haven't finished checking all the errors, but so far I found a couple of wrong constants (see issue #4935 and my other PR #4936). Once done I will mark this as, ready. Any help on this is welcome 😁

[Marcondiro]

Some tests on __c_anonymous_xsk_tx_metadata_union and its variants are failing.

Discusison #4940 was opened to understand how to address this. Should we
A- rename the variants (xsk_tx_metadata_request, xsk_tx_metadata_completion) adding the prefix or
B- explicitly skip the variants from CI?