playwright: wait until distro and arch have been initialized

On-prem the distro and architecture are set after the wizard has been
opened. This triggers a reload of the image types and makes the tests
very flaky.

schutzbot/playwright_tests.sh

@@ -81,6 +81,7 @@ sudo podman run \
      --net=host \
      -v "$PWD:/tests" \
      -v '/etc:/etc' \
+     -v '/etc/os-release:/etc/os-release' \
      --privileged  \
      --rm \
      --init \