Add github CI for image building (beyond-all-reason#1344)

* added image build CI file (#2)

* updated to create tagged image on release

* added sha tagged image, and deduplicated builds

* specified step name

Author: ChocoboCoding

.github/workflows/build.yml

@@ -0,0 +1,39 @@
+name: build prod container image and push to registry
+
+on:
+  push:
+    branches:
+      - main
+  release:
+    types:
+      - published
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    name: Build prod container
+    permissions:
+      packages: write
+      contents: read
+    env:
+      REGISTRY: ghcr.io
+      IMAGE: ghcr.io/${{ github.repository }}
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+
+    - name: Login to registry
+      run: buildah login -u ${{ github.actor }} -p ${{ secrets.GITHUB_TOKEN }} $REGISTRY
+
+    - name: Build image
+      run: buildah bud -t $IMAGE:latest .
+
+    - name: Push latest image
+      run: buildah push $IMAGE:latest
+
+    - name: Push sha tagged image
+      run: buildah push $IMAGE:latest $IMAGE:${{ github.sha }}
+
+    - name: Push release tagged image
+      if: github.event_name == 'release'
+      run: buildah push $IMAGE:latest $IMAGE:${{ github.event.release.tag_name }}