CI: test skips are failures

In CI we should never get a skip, so turn them into failures to make
sure we notice.

This is enabled only for the configuration where we build everything. If
anything is disabled, skips are expected.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>

.gitlab-ci.yml

@@ -105,6 +105,7 @@ build-native-meson-default-options:
       -Doptimization=0
       -Db_coverage=true
       -Dwerror=true
+      -Dtest-skip-is-failure=true
   extends: .build-native-meson
   after_script:
   - ninja -C build-* coverage-html