NO-JIRA: chore(gha): pin github runner to ubuntu-22.04 to avoid flaky failures in podman

Author: jiridanek

.github/workflows/build-notebooks-TEMPLATE.yaml

@@ -18,7 +18,7 @@ name: Build & Publish Notebook Servers (TEMPLATE)
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     env:
       # GitHub image registry used for storing $(CONTAINER_ENGINE)'s cache
       CACHE: "ghcr.io/${{ github.repository }}/workbench-images/build-cache"
@@ -97,6 +97,7 @@ jobs:
 
       - name: Configure Podman
         run: |
+          set -x
           mkdir -p $HOME/.config/containers/
           cp ci/cached-builds/containers.conf $HOME/.config/containers/containers.conf
           cp ci/cached-builds/storage.conf $HOME/.config/containers/storage.conf