adding docker build workflow for arm64 images (#770)

* build: added arm64 docker build

* build: undo typo

* build: remove whitespace

* build: test workflow

* build: test workflow

* build: build arm first

* build: build arm first

* build: using nix arm64 base image

* build: set up qemu

* build: seccomp set to unconfined

* build: create nix config

* build: split arm workflow

* build: reset on release

* build: testing --extra-platforms flag

* build: testing --extra-platforms flag

* build: testing --extra-platforms flag

* build: reset on release

.github/workflows/docker-publish-arm.yml

@@ -0,0 +1,61 @@
+name: Publish Docker Image ARM
+
+on:
+  release:
+    types: [published]
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: 'Tag to build and publish'
+        required: true
+        default: 'latest'
+
+env:
+  REGISTRY: docker.io
+  IMAGE_NAME: thesimplekid/cdk-mintd
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          tags: |
+            type=raw,value=latest,enable=${{ github.event_name == 'release' }}
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=ref,event=branch
+            type=ref,event=pr
+            type=sha
+            ${{ github.event.inputs.tag != '' && github.event.inputs.tag || '' }}
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          platforms: linux/arm64
+          file: ./Dockerfile.arm
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max