Tweak .gitlab-ci.yml for new Gitlab requirment

Gitlab 15 requires slightly different configuration to generate
Cobertura coverage reports. See:

https://docs.gitlab.com/ee/ci/yaml/artifacts_reports.html#artifactsreportscoverage_report

.gitlab-ci.yml

@@ -153,7 +153,9 @@ Python Lint:
 Python Test:
   artifacts:
     reports:
-      cobertura: coverage.xml
+      coverage_report:
+        coverage_format: cobertura
+        path: coverage.xml
       junit: junit.xml
   needs:
     - Poetry