ci: Run coverage target by default

We're just a "ninja coverage" away from getting the full report,
it is not that much extra to the pipeline. Also, fix bugs that
accumulated since the manual task was added, e.g. let the full
built+tested tree available on the coverity stage.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1535

.gitlab-ci.yml

@@ -71,21 +71,17 @@ test-mutter:
     NO_AT_BRIDGE: "1"
   script:
     - bash -x ./.gitlab-ci/run-tests.sh
-  artifacts:
-    expire_in: 1 day
-    paths:
-      - build
   only:
     - merge_requests
     - /^.*$/
   artifacts:
+    expire_in: 1 day
     reports:
       junit: "build/${CI_JOB_NAME}-report.xml"
     name: "mutter-${CI_JOB_NAME}-${CI_COMMIT_REF_NAME}"
     when: always
     paths:
-      - "build/meson-logs"
-      - "build/${CI_JOB_NAME}-report.xml"
+      - build
 
 test-mutter-coverage:
   stage: coverage
@@ -97,12 +93,12 @@ test-mutter-coverage:
     - cat build/meson-logs/coverage.txt
   artifacts:
     paths:
-      - build/meson-logs
-  when: manual
-  except:
-    refs:
-      - tags
-      - master
+      - build/meson-logs/coveragereport
+  coverage: '/^TOTAL.*\s+(\d+\%)$/'
+  when: always
+  only:
+    - merge_requests
+    - /^.*$/
 
 can-build-gnome-shell:
   stage: test