ci: add link to coverage report in build logs

Makes coverage info a bit easier to access and discover.

Signed-off-by: Simon Ser <contact@emersion.fr>
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 5093f58..ec1f274 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -58,6 +58,7 @@
     - ninja -C build/
     - ninja -C build/ test
     - ninja -C build/ -j1 coverage-xml coverage-html
+    - echo "Coverage report can be browsed at $CI_JOB_URL/artifacts/file/build/meson-logs/coveragereport/index.html"
   artifacts:
     when: always
     paths: