Migrate to reusable workflow

Author: nint8835

.github/workflows/build.yml

@@ -5,17 +5,14 @@ on:
     branches:
       - main
 
+permissions:
+  contents: read
+  packages: write
+  attestations: write
+  id-token: write
+
 jobs:
   build:
-    name: Build Docker Image
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - name: Push to GitHub Packages
-        uses: docker/build-push-action@v1
-        with:
-          username: ${{ github.actor }}
-          password: ${{ secrets.GITHUB_TOKEN }}
-          registry: ghcr.io
-          repository: nint8835/embassy
-          tags: latest
+    uses: nint8835/workflows/.github/workflows/docker-build.yaml@main
+    with:
+      image_name: nint8835/embassy