podwrap: add support for python3 execution

podwrap/podman-wrapper.sh

@@ -57,8 +57,11 @@ pw_userns_gid=${pw_userns_gid:-1000}
 
 mkdir -p "$worktree/artifacts"
 
+cmd="bash"
+[[ "$prog" == *.py ]] && cmd="python3"
+
 exec podman run -it --rm --name "$container_name" \
      -v "$worktree/artifacts:/artifacts" \
      -v "$worktree:/host:ro" \
      $pw_args \
-     "$pw_image" bash "$prog" $@
+     "$pw_image" "$cmd" "$prog" $@