mkosi: pin CentOS8 kernel to working version

Newer kernels are affected by a regression that causes a kernel panic
on boot when using cgroupv2, so pin them for now. Can be reverted once
that problem is fixed.

mkosi.images/system/mkosi.conf.d/10-centos-fedora.conf

@@ -13,7 +13,6 @@ Packages=
         glib2
         iproute
         iproute-tc
-        kernel-core
         libcap-ng-utils
         netcat
         openssh-server

mkosi.images/system/mkosi.conf.d/10-centos/mkosi.conf

@@ -2,7 +2,3 @@
 
 [Match]
 Distribution=centos
-
-[Content]
-Packages=
-        kernel-modules # For squashfs support

mkosi.images/system/mkosi.conf.d/10-centos/mkosi.conf.d/10-centos8.conf

@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+[Match]
+Release=8
+
+[Content]
+Packages=
+        kernel-core-4.18.0-521.el8
+        kernel-modules-4.18.0-521.el8 # For squashfs support

mkosi.images/system/mkosi.conf.d/10-centos/mkosi.conf.d/10-centos9.conf

@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+[Match]
+Release=9
+
+[Content]
+Packages=
+        kernel-core
+        kernel-modules

mkosi.images/system/mkosi.conf.d/10-fedora.conf

@@ -8,3 +8,4 @@ Packages=
         btrfs-progs
         compsize
         f2fs-tools
+        kernel-core