Fix Docker login action password line break

Author: denji

.github/workflows/docker-image.yml

@@ -103,7 +103,7 @@ jobs:
         with:
           registry: ghcr.io
           username: ${{ github.actor }}
-          password: ${{ secrets.GITHUB_TOKEN }}\
+          password: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Login to DockerHub
         uses: docker/login-action@v4