CI: drop the merge request check

Effectively obsolete and now broken, see
https://gitlab.freedesktop.org/freedesktop/ci-templates/-/issues/81

Part-of: <https://gitlab.freedesktop.org/xorg/driver/xf86-input-libinput/-/merge_requests/75>

.gitlab-ci.yml

@@ -81,18 +81,3 @@ check-commits:
     reports:
       junit: results.xml
   allow_failure: true
-
-#
-# Verify that the merge request has the allow-collaboration checkbox ticked
-#
-check-merge-request:
-  extends:
-    - .fdo.ci-fairy
-  stage: test
-  script:
-    - ci-fairy check-merge-request --require-allow-collaboration --junit-xml=results.xml
-  artifacts:
-    when: on_failure
-    reports:
-      junit: results.xml
-  allow_failure: true