Add CI reuse check (KhronosGroup#525)

Reuse the VK job to check the license on PR

Author: Victor Lomuller

.github/workflows/presubmit.yml

@@ -131,3 +131,16 @@ jobs:
         run: |
           cmake -S tests/pkg_config -B tests/pkg_config/build/ -D CMAKE_PREFIX_PATH=${GITHUB_WORKSPACE}/build/install
           cmake --build tests/pkg_config/build/
+
+  license-check:
+    name: Verify repository license compliance
+    runs-on: ubuntu-latest
+    # We now refer to the container by its SHA instead of the name, to prevent
+    # caching problems when updating the image.
+    # container: khronosgroup/docker-images:asciidoctor-spec.20240726
+    container: khronosgroup/docker-images@sha256:724f67d8562445523644abf017d5d192b369fafc122de75e9d26792c649821a0
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: REUSE license checker
+        run: reuse lint