Actions: automatically add comment on PR

.forgejo/workflows/deploy_hosted.yml

@@ -62,5 +62,17 @@ jobs:
       - name: unzipping remote file
         run: ssh hetzner "cd /root/staging && rm -rf ${{ github.ref_name }} && unzip ${{ github.ref_name }}.zip && rm -rf /root/public/${{ github.ref_name }} && mv /root/staging/${{ github.ref_name }}/ /root/public/ && rm ${{ github.ref_name }}.zip"
 
+      - name: Extract PR number
+        run: echo "PR_NUMBER=$(echo $FORGEJO_REF_NAME | cut -d'/' -f3)" >> $FORGEJO_ENV
+
+      - name: add comment to PR
+        if: env.PR_NUMBER != ''
+        run: |
+          curl -X POST "https://source.mapcomplete.org/api/v1/repos/${FORGEJO_REPOSITORY}/issues/${PR_NUMBER}/comments" \
+          -H "Content-Type: application/json" \
+          -H "Authorization: token $FORGEJO_TOKEN" \
+          -d '{"body": "This PR has been deployed and is (temporarily) available on https://builds.mapcomplete.org/${PR_NUMBER}"}'
+        env:
+          FORGEJO_TOKEN: ${{ secrets.FORGEJO_TOKEN }}