Turned off CI/CD due to dysfunct runners.

Refactored test jobs.

.gitlab-ci.yml

-test_theory_common:
+# Do not run pipeline
+#
+# For technical reasons there is currently no runner available. 
+# Thus, all pipelines fail. This blocks merge requests.
+workflow:
+  rules:
+    - when: never
+
+# Template for Prolog test jobs
+.prolog_test:
     image: swipl:8.2.2
     stage: test
-    variables:
-        REPORT_PATH: coverage_irrelevance_common
     script:
-        - swipl -s tests/irrelevance_common.plt -t 'show_coverage(run_tests,[user])' > "$REPORT_PATH"
+        - swipl -s "tests/${TEST_FILE}" -t 'show_coverage(run_tests,[${TEST_MODULE}])' > "${REPORT_PATH}"
     timeout: 5m
     artifacts:
         paths:
             - "$REPORT_PATH"
         expire_in: 3 days
+
+
+test_theory_common:
+    extends: .prolog_test
+    variables:
+        TEST_FILE: irrelevance_common.plt
+        TEST_MODULE: user
+        REPORT_PATH: coverage_irrelevance_common
         
-test_web_api_explanation_integration:
-    image: swipl:8.2.2
-    stage: test
+test_web_api:
+    extends: .prolog_test
     variables:
+        TEST_FILE: web_api.plt
+        TEST_MODULE: web_api
         REPORT_PATH: coverage_web_api
-    script:
-        - swipl -s tests/web_api_expl_integration.plt -t 'show_coverage(run_tests,[web_api])' > "$REPORT_PATH"
-    timeout: 5m
-    artifacts:
-        paths:
-            - "$REPORT_PATH"
-        expire_in: 3 days