Test for yum install does not work if builder tag contains `docker`

The test verifies the following:

if "docker" in os.environ.get("CI_RUNNER_TAGS", "") and os.path.exists(
            yum_requirements_file
        ):
    ...

The CI_RUNNER_TAGS for the shell builder says docker-build, and therefore this test will also succeed then, whereas it shouldn't.

The solution would be to split the tags, and compare to "exactly" docker and not to just contain it.

Test for yum install does not work if builder tag **contains** `docker`