ci: yaml-toml-shell-test: use pyutils container

Currently the yaml-toml-shell-test extends the python-test job to make
use of the python packages available there. But the python-test also
generates artifacts which yaml-toml-shell-test does not need to do.

Instead of extending the python-test job, avoid extra work by just using
the pyutils container directly.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32340>

.gitlab-ci/test/gitlab-ci.yml

@@ -45,7 +45,7 @@ rustfmt:
 
 yaml-toml-shell-test:
   extends:
-    - python-test
+    - .use-debian/x86_64_pyutils
     - .no-auto-retry  # this job can't be flaky
   stage: code-validation
   script: