ci/b2c: rename B2C_TEST_SCRIPT to B2C_CONTAINER_CMD to match the automatic import

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/26653>

.gitlab-ci/b2c/generate_b2c.py

@@ -38,7 +38,6 @@ env = Environment(loader=FileSystemLoader(path.dirname(values['job_template'])),
 template = env.get_template(path.basename(values['job_template']))
 
 values['ci_job_id'] = environ['CI_JOB_ID']
-values['container_cmd'] = values['test_script']
 try:
     values['tags'] = json.loads(environ['CI_RUNNER_TAGS'])
 except json.decoder.JSONDecodeError:

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

@@ -343,7 +343,7 @@ clang-format:
       [ -d "$CI_B2C_ARTIFACTS" ] || exit 1
       [ -d "$CI_COMMON_SCRIPTS" ] || exit 1
 
-      export B2C_TEST_SCRIPT="bash -euc 'tar xf ${INSTALL_TARBALL_NAME}; ./install/common/init-stage2.sh'"
+      export B2C_CONTAINER_CMD="bash -euc 'tar xf ${INSTALL_TARBALL_NAME}; ./install/common/init-stage2.sh'"
 
       # The Valve CI gateway receives jobs in a YAML format. Create a
       # job description from the CI environment.