Update release.yml

Author: egil

.github/workflows/release.yml

@@ -82,7 +82,7 @@ jobs:
         run: |
           git add CHANGELOG.md
           git commit -S -m "Updated CHANGELOG.md for ${{ env.NBGV_SimpleVersion }} release"
-          echo "RELEASE_COMMIT_HASH=$((git rev-parse stable))" >> $GITHUB_ENV
+          echo "RELEASE_COMMIT_HASH=git rev-parse stable" >> $GITHUB_ENV
 
       - name: 🛠️ Building library in release mode
         run: dotnet pack src/ -c release -p:ContinuousIntegrationBuild=true