.github/workflows: Bump 6.12 kernel to final v6.12.0 version

Now that the 6.12 kernel has been released we don't have to test against
an -rc kernel anymore.

Signed-off-by: Toke Høiland-Jørgensen <[email protected]>

Author: tohojo

.github/workflows/selftests.yml

@@ -12,7 +12,7 @@ jobs:
     strategy:
       matrix:
         KERNEL_VERSION:
-          - "6.12.0-0.rc2.24.fc42"
+          - "6.12.0-65.fc42"
           - "6.10.14-200.fc40"
           - "6.6.14-200.fc39"
           - "6.1.9-200.fc37"