ci/ci-tron: default HWCI_TEST_SCRIPT to deqp-runner, as it's almost always what's run

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34710>

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

@@ -380,6 +380,9 @@ yaml-toml-shell-py-test:
     B2C_JOB_TEMPLATE: "${CI_B2C_ARTIFACTS}/b2c.yml.jinja2.jinja2"
     JOB_FOLDER: "job_folder"
 
+    # Assume by default this is running deqp, as that's almost always true
+    HWCI_TEST_SCRIPT: install/deqp-runner.sh
+
   needs:
     - job: python-artifacts
       artifacts: true