gitlab: Disable check-python-tox

Set this test to be manually run, until failures can be fixed.

Suggested-by: John Snow <jsnow@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

.gitlab-ci.d/static_checks.yml

@@ -46,4 +46,6 @@ check-python-tox:
     QEMU_TOX_EXTRA_ARGS: --skip-missing-interpreters=false
   needs:
     job: python-container
+  rules:
+    - when: manual
   allow_failure: true