Export build artifacts for .deb packages

This uses shrink/actions-docker-extract and actions/upload-artifact to
take the completed .deb and .changes files out of a container that has
terminated, then upload them as a build artifact. This artifact is a
single zip file. We expect to eventually send a (GitHub) repository
event to apt-lib, which will trigger a workflow there to download the
build artifact, place the files in the appropriate incoming area, and
refresh the (APT) repository.

.github/workflows/build-apache-latest.yml

@@ -31,3 +31,26 @@ jobs:
           push: true
           tags: 'ghcr.io/mlibrary/lauth/lauth-apache:${{ github.sha }}, ghcr.io/mlibrary/lauth/lauth-apache:latest'
           file: ./apache/Dockerfile
+
+      - name: Build .deb packages
+        uses: docker/build-push-action@v5
+        with:
+          context: ./
+          target: packages
+          push: false
+          load: true
+          tags: 'lauth-debs:latest'
+          file: ./apache/Dockerfile
+
+      - uses: shrink/actions-docker-extract@v3
+        id: extract
+        with:
+          image: lauth-debs:latest
+          path: /debs/out/.
+          destination: dist
+
+      - name: Archive lauth-apache .deb packages
+        uses: actions/upload-artifact@v4
+        with:
+          name: lauth-apache-debs_${{ github.sha }}
+          path: dist/*