github: mkosi: skip archlinux-arm tests for now

Author: kaniini

.github/workflows/mkosi-tests.yaml

@@ -18,6 +18,9 @@ jobs:
       matrix:
         distro: [arch, debian, fedora, centos, opensuse]
         runner: [ubuntu-24.04, ubuntu-24.04-arm]
+        exclude:
+          - distro: arch
+            runner: ubuntu-24.04-arm
 
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683