ci: add container build workflow

Add prebuilt build images and a publish workflow to speed CI by reusing heavy dependencies.

.github/workflows/containers.yml

@@ -0,0 +1,38 @@
+name: containers
+
+on:
+  push:
+    branches:
+      - dev
+    paths:
+      - packages/containers/**
+      - .github/workflows/containers.yml
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  packages: write
+
+jobs:
+  build:
+    runs-on: blacksmith-4vcpu-ubuntu-2404
+    env:
+      REGISTRY: ghcr.io/${{ github.repository_owner }}
+      TAG: "24.04"
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: ./.github/actions/setup-bun
+
+      - name: Login to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push containers
+        run: bun ./packages/containers/script/build.ts --push
+        env:
+          REGISTRY: ${{ env.REGISTRY }}
+          TAG: ${{ env.TAG }}