CI: drop the ci-fairy check-mr job

The only thing this checked was the checkbox for allowing maintainers to
edit the MR. Changed permissions checks now fail this job but luckily
the setting it checked has been the default for years anyway so we can
drop it.

https://gitlab.freedesktop.org/freedesktop/ci-templates/-/issues/81

Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2116>
(cherry picked from commit cd5666a4e0)

.gitlab-ci.yml

@@ -334,24 +334,6 @@ check-commits:
       junit: results.xml
   allow_failure: true
 
-#
-# Verify that the merge request has the allow-collaboration checkbox ticked
-#
-check-merge-request:
-  extends:
-    - .fdo.ci-fairy
-  needs: []
-  stage: test
-  rules:
-    - if: $CI_PIPELINE_SOURCE == 'merge_request_event'
-  script:
-    - ci-fairy check-merge-request --require-allow-collaboration --junit-xml=results.xml
-  artifacts:
-    when: on_failure
-    reports:
-      junit: results.xml
-  allow_failure: true
-
 #
 # Workflow rules needed due to:
 # https://gitlab.freedesktop.org/freedesktop/freedesktop/-/issues/438