Fix bug in release workflow

Author: pealtrufo

.github/workflows/release.yml

@@ -45,7 +45,7 @@ jobs:
            python3 setup.py --version > version     
            
       - name: Get bumpversion
-        run: echo ::set-env name=VERSION::$(grep -i 'current_version = ' setup.cfg | head -1 | tr -d 'current_version = ')
+        run: echo "VERSION"=$(grep -i 'current_version = ' setup.cfg | head -1 | tr -d 'current_version = ') >> $GITHUB_ENV
 
       - name: Create Release
         id: create_release