build: convert ::set-output to $GITHUB_OUTPUT

Signed-off-by: Hidde Beydals <[email protected]>

Author: hiddeco

.github/workflows/release.yaml

@@ -31,7 +31,7 @@ jobs:
           if [[ $GITHUB_REF == refs/tags/* ]]; then
             VERSION=${GITHUB_REF/refs\/tags\//}
           fi
-          echo ::set-output name=VERSION::${VERSION}
+          echo "version=${VERSION}" >> $GITHUB_OUTPUT
       - uses: actions/setup-go@v2
         with:
           go-version: 1.19.x
@@ -65,7 +65,7 @@ jobs:
             fluxcd/${{ env.CONTROLLER }}
             ghcr.io/fluxcd/${{ env.CONTROLLER }}
           tags: |
-            type=raw,value=${{ steps.prep.outputs.VERSION }}
+            type=raw,value=${{ steps.prep.outputs.version }}
       - name: Docker push
         uses: docker/build-push-action@v2
         with:
@@ -80,8 +80,8 @@ jobs:
         env:
           COSIGN_EXPERIMENTAL: 1
         run: |
-          cosign sign fluxcd/${{ env.CONTROLLER }}:${{ steps.prep.outputs.VERSION }}
-          cosign sign ghcr.io/fluxcd/${{ env.CONTROLLER }}:${{ steps.prep.outputs.VERSION }}
+          cosign sign fluxcd/${{ env.CONTROLLER }}:${{ steps.prep.outputs.version }}
+          cosign sign ghcr.io/fluxcd/${{ env.CONTROLLER }}:${{ steps.prep.outputs.version }}
       - name: GoReleaser publish signed SBOM
         if: startsWith(github.ref, 'refs/tags/v')
         uses: goreleaser/goreleaser-action@v3