Actions: Other method for branch name

.github/workflows/Build.yml

@@ -26,13 +26,14 @@ jobs:
       # Initialize build branch
       - name: Initialize build branch
         run: |
+          SOURCE_BRANCH_NAME=$(echo ${GITHUB_REF#refs/heads/})
           git config --global user.name 'Git Workflow Bot'
           git config --global user.email 'noreply@kozelkaricsi.hu'
           git fetch --all --unshallow
-          BRANCH_NAME="${GITHUB_REF_NAME}-build"
+          BRANCH_NAME="${SOURCE_BRANCH_NAME}-build"
           git fetch origin $BRANCH_NAME --unshallow || true  # Allow failure if branch doesn't exist
           git switch $BRANCH_NAME || git switch -c $BRANCH_NAME
-          git merge ${GITHUB_REF_NAME} -m "Update branch [skip ci]"
+          git merge ${SOURCE_BRANCH_NAME} -m "Update branch [skip ci]"
           rm -rf dist
 
       # Install dependencies