ci: allow GHCR release token fallback

Author: Ryson-32

.github/workflows/release.yml

@@ -84,8 +84,8 @@ jobs:
       - uses: docker/login-action@v3
         with:
           registry: ghcr.io
-          username: ${{ github.actor }}
-          password: ${{ github.token }}
+          username: ${{ secrets.GHCR_USERNAME || github.actor }}
+          password: ${{ secrets.GHCR_PAT || github.token }}
 
       - name: Build and push ${{ matrix.platform }} image by digest
         id: build_image
@@ -140,8 +140,8 @@ jobs:
       - uses: docker/login-action@v3
         with:
           registry: ghcr.io
-          username: ${{ github.actor }}
-          password: ${{ github.token }}
+          username: ${{ secrets.GHCR_USERNAME || github.actor }}
+          password: ${{ secrets.GHCR_PAT || github.token }}
 
       - name: Download image digests
         uses: actions/download-artifact@v4