chore(ci): add release workflow

Author: calebevans

.github/release.yml

@@ -0,0 +1,7 @@
+   categories:
+     - title: Features
+       labels: [feature, enhancement]
+     - title: Fixes
+       labels: [bug, fix, patch]
+     - title: Other
+       labels: [chore]

.github/workflows/release.yml

@@ -0,0 +1,109 @@
+name: Release
+
+on:
+  push:
+    tags: ['v*.*.*']
+
+env:
+  IMAGE_NAME: podmortem-operator
+  DOCKERFILE: ./src/main/docker/Dockerfile.native
+  DEP_STAGE: dependencies
+
+jobs:
+  warm-cache:
+    runs-on: self-hosted
+    permissions: {contents: read, packages: write}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: docker/setup-buildx-action@v3
+
+      - name: Login to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GH_PAT }}
+
+      - name: Build deps layer
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: ${{ env.DOCKERFILE }}
+          target: ${{ env.DEP_STAGE }}
+          push: true
+          platforms: linux/amd64
+          cache-from: type=gha,scope=deps
+          cache-to: |
+            type=gha,mode=max,scope=deps
+            type=registry,ref=ghcr.io/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}:deps-cache,mode=max
+          tags: ghcr.io/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}:deps-cache
+          build-args: GITHUB_USER=${{ github.actor }}
+          secrets: GITHUB_TOKEN=${{ secrets.GITHUB_TOKEN }}
+
+  build-arch:
+    needs: warm-cache
+    runs-on: self-hosted
+    permissions: {contents: read, packages: write}
+    strategy:
+      matrix:
+        arch: [amd64, arm64]
+        include:
+          - arch: amd64
+            platform: linux/amd64
+          - arch: arm64
+            platform: linux/arm64
+    steps:
+      - uses: actions/checkout@v4
+      - uses: docker/setup-buildx-action@v3
+      - uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GH_PAT }}
+
+      - name: Build & push ${{ matrix.arch }}
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: ${{ env.DOCKERFILE }}
+          platforms: ${{ matrix.platform }}
+          push: true
+          cache-from: |
+            type=gha,scope=deps
+            type=gha,scope=build-${{ matrix.arch }}
+          cache-to: type=gha,mode=max,scope=build-${{ matrix.arch }}
+          tags: |
+            ghcr.io/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}:${{ github.ref_name }}-${{ matrix.arch }}
+          build-args: GITHUB_USER=${{ github.actor }}
+          secrets: GITHUB_TOKEN=${{ secrets.GITHUB_TOKEN }}
+
+  manifest:
+    needs: build-arch
+    runs-on: self-hosted
+    permissions: {contents: read, packages: write}
+    steps:
+      - uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GH_PAT }}
+
+      - name: Create manifest list
+        run: |
+          for TAG in ${{ github.ref_name }} latest; do
+            docker buildx imagetools create \
+              -t ghcr.io/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}:${TAG} \
+                ghcr.io/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}:${{ github.ref_name }}-amd64 \
+                ghcr.io/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}:${{ github.ref_name }}-arm64
+          done
+
+  release-notes:
+    needs: manifest
+    runs-on: self-hosted
+    permissions: {contents: write}
+    steps:
+      - name: Generate GitHub Release
+        uses: softprops/action-gh-release@v1
+        with:
+          tag_name: ${{ github.ref_name }}
+          generate_release_notes: true