Adapted release hook to branch 4.0.x

Author: matrei

.github/workflows/release.yml

@@ -12,6 +12,7 @@ jobs:
       -   name: Checkout repository
           uses: actions/checkout@v2
           with:
+            ref: 4.0.x
             token: ${{ secrets.GH_TOKEN }}
       -   uses: gradle/wrapper-validation-action@v1
       -   name: Set up JDK
@@ -56,6 +57,7 @@ jobs:
             github_token: ${{ secrets.GITHUB_TOKEN }}
             author_name: ${{ secrets.GIT_USER_NAME }}
             author_email: $${ secrets.GIT_USER_EMAIL }}
+            branch: 4.0.x
             message: 'Set version to next SNAPSHOT'
       -   name: Export Gradle Properties
           uses: micronaut-projects/github-actions/export-gradle-properties@master