use arm64 github runner for building arm image

.github/workflows/main.yml

@@ -1,14 +1,9 @@
 on: push
+
 jobs:
-  build:
+  build-amd64:
     runs-on: ubuntu-latest-64-cores
     steps:
-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@v2
-
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v2
-
       - name: Log into Docker Hub
         uses: docker/login-action@v2
         with:
@@ -37,6 +32,20 @@ jobs:
         run: |
           docker push cs50/cli:amd64
 
+  build-arm64:
+    runs-on: ubuntu-latest-64-cores-arm
+    steps:
+      - name: Log into Docker Hub
+        uses: docker/login-action@v2
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
       - name: Build for linux/arm64
         uses: docker/build-push-action@v3
         with: