packit: Re-disable centos-stream-10

Installing kernel-modules-extra as a workaround for
https://issues.redhat.com/browse/RHEL-29893 doesn't work reliably:
Current TF image has an outdated running kernel 6.9.0-0.rc2.1.el10 while
dnf sees the current kernel 6.9.0-7.el10, so the installed modules don't
match.

This is just too broken still, so go back to ignoring CentOS/RHEL 10
until this is fixed.

packit.yaml

@@ -36,7 +36,8 @@ jobs:
     packages: [cockpit-machines-centos]
     targets:
     - centos-stream-9
-    - centos-stream-10
+    # blocked on https://issues.redhat.com/browse/RHEL-29893
+    # - centos-stream-10
 
   - job: tests
     packages: [cockpit-machines-fedora]
@@ -51,7 +52,8 @@ jobs:
     trigger: pull_request
     targets:
       - centos-stream-9
-      - centos-stream-10
+      # blocked on https://issues.redhat.com/browse/RHEL-29893
+      # - centos-stream-10
 
   - job: copr_build
     trigger: release