fix set-env of GitHub Actions

.github/workflows/release-rc.yml

@@ -35,7 +35,7 @@ jobs:
     - name: Get SemVer
       run: |
         semver=`npm run version --silent`
-        echo ::set-env name=SEMVER::$semver
+        echo "SEMVER=$semver" >> $GITHUB_ENV
 
     - name: Docker Tags by SemVer
       uses: weseek/ghaction-docker-tags-by-semver@v1.0.3

.github/workflows/release.yml

@@ -28,7 +28,7 @@ jobs:
         npm --no-git-tag-version version patch
         export RELEASE_VERSION=`npm run version --silent`
         sh ./bin/github-actions/update-readme.sh
-        echo ::set-env name=RELEASE_VERSION::$RELEASE_VERSION
+        echo "RELEASE_VERSION=$RELEASE_VERSION" >> $GITHUB_ENV
         echo ::set-output name=RELEASE_VERSION::$RELEASE_VERSION
 
     - name: Checkout, Commit, Tag and Push
@@ -69,7 +69,7 @@ jobs:
     - name: Determine suffix
       run: |
         [[ ${{ matrix.flavor }} = "nocdn" ]] && suffix="-nocdn" || suffix=""
-        echo ::set-env name=SUFFIX::$suffix
+        echo "SUFFIX=$suffix" >> $GITHUB_ENV
 
     - name: Set up Docker Buildx
       uses: docker/setup-buildx-action@v1