CI: Drop ppc64le and s390x from multiarch tests

Support was dropped from the action we were using for this.

Signed-off-by: Stephen Gallagher <sgallagh@redhat.com>

Author: sgallagher

.github/workflows/multiarch.yaml

@@ -14,9 +14,6 @@ jobs:
           - arch: aarch64
             distro: fedora_latest
           - arch: ppc64le
-            distro: fedora_latest
-          - arch: s390x
-            distro: fedora_latest
 
     steps:
       - uses: actions/checkout@v4