CI: fix deprecation (set-output)

Author: cknitt

.github/workflows/ci.yml

@@ -164,12 +164,12 @@ jobs:
       id: vars
       env:
         COMMIT_SHA: ${{ github.event.pull_request.head.sha || github.sha }}
-      run: echo "::set-output name=sha_short::${COMMIT_SHA:0:7}"
+      run: echo "sha_short=${COMMIT_SHA:0:7}" >> $GITHUB_OUTPUT
 
     - name: Store tag name
       id: tag_name
       if: startsWith(github.ref, 'refs/tags/')
-      run: echo ::set-output name=tag::${GITHUB_REF#refs/*/}
+      run: echo "tag=${GITHUB_REF#refs/*/}" >> $GITHUB_OUTPUT
 
     - name: Increment pre-release version
       if: github.ref == 'refs/heads/master'