ci/bare-metal: Remove "stage: test" from .baremetal-test.

This is not one of the valid stages in the top level "stages:"
declaration, you're supposed to get your stage from your
test-source-dep.yml include.  Avoids issues when .baremetal-test gets
included after your test-source-dep.

Acked-by: Daniel Stone <daniels@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17146>

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

@@ -120,7 +120,6 @@
     - .test
   # Cancel job if a newer commit is pushed to the same branch
   interruptible: true
-  stage: test
   before_script:
     - !reference [default, before_script]
     # Use this instead of gitlab's artifacts download because it hits packet.net