ubuntu: when building stable image, don't take pc-kernel from beta

The pc-kernel version in 26.04/beta is kernel 6.17, which uses different
components from what is currently declared in the model.

This used to be necessary when there was no kernel in 26.04/stable, but now
there is a 6.8 version in 26.04/stable. The available components match what's
in the model.

Signed-off-by: Olivier Gayot <olivier.gayot@canonical.com>

live-build/ubuntu/hooks/030-ubuntu-live-system-seed.binary

@@ -100,14 +100,13 @@ else
     # because it allows us to override snaps. But we don't want all snaps from
     # edge like the dangerous model has, we want most of them from stable
     # excluding:
-    # * pc-kernel - which currently does not exist on stable
     # * snapd (for TPM/FDE)
     # * firmware-updater (for TPM/FDE)
     # * desktop-security-center (for TPM/FDE)
     while read -r snap_arg; do
         prepare_args+=("$snap_arg")
     done < <(get_snaps_args /usr/share/livecd-rootfs/live-build/"${PROJECT}"/ubuntu-classic-amd64.model \
-    | grep -v -F -e pc-kernel -e snapd -e firmware-updater -e desktop-security-center)
+    | grep -v -F -e snapd -e firmware-updater -e desktop-security-center)
 fi
 
 for comp in $(get_all_components "$model"); do