Kernel pin for 6.11.11 in stable images

[ledif]

We should follow Bluefin's lead and pin the kernel for stable images to avoid a regression in brightness control for some AMD-based laptops.

References:

• Pin kernel to 6.11.8 bluefin#2103
• https://bugzilla.redhat.com/show_bug.cgi?id=2333789

[ledif]

There's an update on the Bugzilla stating that a fix has been merged and should appear in 6.12.9: https://bugzilla.redhat.com/show_bug.cgi?id=2333789#c7

[inffy]

6.12.9 was released today, I guess we will get that to fedora soon(ish), not yet on bodhi so propably during next week

[RealVishy]

Next CoreOS kernel based on what's in testing is going to be 6.12.7.

https://bugzilla.redhat.com/show_bug.cgi?id=2333543
https://gitlab.freedesktop.org/drm/amd/-/issues/3853

Apparently it has been fixed in 6.13 but the backport of the fix in 6.12.9 is still having some issues, so I propose we pin the kernel to 6.11.11 until the 6.12 backport is confirmed working fully or when 6.13 makes it to coreOS.

[inffy]

I guess it doesn't really matter if its 6.11.8 or 6.11.11. This seems only be affecting Vega gpus atleast looking at the bug reports