fix: change default runner to linux-arm64 in CI workflow

Signed-off-by: Nikolai Emil Damm <[email protected]>

Author: devantler

.github/workflows/ci-gitops-test.yaml

@@ -12,7 +12,7 @@ on:
       RUNNER:
         required: false
         type: string
-        default: ubuntu-latest
+        default: linux-arm64
       HOSTS_FILE:
         required: false
         type: string