ci: update docker workflow

.github/workflows/docker.yml

@@ -0,0 +1,29 @@
+name: Build and Push Docker Image
+
+on:
+  workflow_dispatch:
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Log in to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Extract commit digest
+        id: vars
+        run: echo "sha8=${GITHUB_SHA::8}" >> $GITHUB_OUTPUT
+
+      - name: Build and Push Docker image
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          platforms: linux/amd64
+          push: true
+          tags: scrolltech/cloak-rpc-auth-proxy:${{ steps.vars.outputs.sha8 }}