Actually enforce REUSE compliance in CI.

Author: PhilippWendler

.github/workflows/reuse.yml

@@ -16,4 +16,3 @@ jobs:
     - uses: actions/checkout@v2
     - name: REUSE Compliance Check
       uses: fsfe/[email protected]
-      continue-on-error: true

.gitlab-ci.yml

@@ -171,5 +171,3 @@ reuse:
     entrypoint: [""]
   script:
     - reuse lint
-  # needs more work
-  allow_failure: true