fix: unpin 6.11.3 kernel

[castrojo]

Do not unpin until 2024-12-17, that's when the next coreos release is due.

[castrojo]

Fixes #1863 - I was off by one point release, we can bump this now as 6.11.6 is in the coreos stream now. This is ready to go!

[befanyt]

There is also a hardcoded pin in kernel-cache that probably needs to be removed.

https://github.com/ublue-os/kernel-cache/blob/89d9c6cf1985af06709d00bb9c70544bc76f8019/.github/workflows/reusable-build.yml#L100-L103

              # Gross Pin... But workaround coreos-stable being on a broken kernel...
              if [[ "${{ matrix.kernel_flavor }}" == "coreos-stable" ]]; then
                image_linux="6.11.3-300.fc41.x86_64"
              fi

[castrojo]

ublue-os/kernel-cache#42