use buildx cache

.github/workflows/docker-eigenda.yml

@@ -20,7 +20,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           submodules: 'recursive'
-          ssh-key: ${{ secrets.SSH_KEY }}
 
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3
@@ -30,6 +29,13 @@ jobs:
         with:
           install: true
 
+      - name: Cache Docker layers
+        uses: actions/cache@v3
+        with:
+          path: /tmp/.buildx-cache
+          key: ${{ runner.os }}-buildx-${{ hashFiles('Dockerfile') }}
+          restore-keys: ${{ runner.os }}-buildx-
+
       - name: Login to GitHub Container Registry
         uses: docker/login-action@v2
         with: