CI: fix syntax for setting environment variables

Author: griggt

.github/workflows/ci.yaml

@@ -374,7 +374,7 @@ jobs:
           ./project/scripts/sbt dist/packArchive
           sha256sum dist/target/scala3-* > dist/target/sha256sum.txt
           ./project/scripts/sbtPublish ";project scala3-bootstrapped ;publishSigned ;sonatypeBundleRelease"
-          echo "name=RELEASE_TAG::${GITHUB_REF#*refs/tags/}" >> $GITHUB_ENV
+          echo "RELEASE_TAG=${GITHUB_REF#*refs/tags/}" >> $GITHUB_ENV
 
       - name: Create GitHub Release
         id: create_gh_release