Fix usage of deprecated set-output, give nicer URL to commit (#916)

`set-output` is deprecated
(https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/)
and the job always printed annoying warning because of that. Fix that to
use `$GITHUB_OUTPUT` instead.

Additionally, instead of printing just a hash of the commit, print a
(clickable) URL to the commit.

.github/workflows/integration-tests.yml

@@ -45,7 +45,8 @@ jobs:
 
       - name: Get last commit author
         id: get_author
-        run: echo "::set-output name=author::$(git log -1 --pretty=format:'%an <%ae> sha1={%H}')"
+        run: >
+          echo "author=$(git log -1 --pretty=format:'%an <%ae>, commit URL: ${{ github.server_url }}/${{ github.repository }}/commit/%H')" >> $GITHUB_OUTPUT
 
       - name: License Header Verification
         working-directory: ci/it