fix env GHCR_REPOSITORY

.github/workflows/docker-image-arm64.yml

@@ -91,6 +91,9 @@ jobs:
       - name: Extract tag
         run: echo "TAG=${GITHUB_REF#refs/tags/}" >> $GITHUB_ENV
 
+      - name: Normalize GHCR repository
+        run: echo "GHCR_REPOSITORY=${GITHUB_REPOSITORY,,}" >> $GITHUB_ENV
+
       - name: Log in to Docker Hub
         uses: docker/login-action@v3
         with: