ci(release): Don't use set-env in GHA (#21372)

See https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands/

Author: BYK

.github/workflows/release.yml

@@ -32,14 +32,14 @@ jobs:
       - id: set-version
         run: |
           if [[ -n '${{ github.event.inputs.version }}' ]]; then
-            echo '::set-env name=RELEASE_VERSION::${{ github.event.inputs.version }}';
+            echo 'RELEASE_VERSION=${{ github.event.inputs.version }}' >> $GITHUB_ENV;
           else
             DATE_PART=$(date +'%y.%-m')
             declare -i PATCH_VERSION=0
             while curl -sf -o /dev/null "https://api.github.com/repos/$GITHUB_REPOSITORY/git/ref/tags/$DATE_PART.$PATCH_VERSION"; do
               PATCH_VERSION+=1
             done
-            echo "::set-env name=RELEASE_VERSION::${DATE_PART}.${PATCH_VERSION}"
+            echo "RELEASE_VERSION=${DATE_PART}.${PATCH_VERSION}" >> $GITHUB_ENV;
           fi
       - uses: actions/checkout@v2
         with: