Migrate from bullseye to bookworm

* Pin bookworm explicitly in parent container image tags
* Update references to bullseye

.github/workflows/docker-publish.yml

@@ -17,7 +17,7 @@ on:
 
 env:
   # Use docker.io for Docker Hub if empty
-  REGISTRY: docker.io 
+  REGISTRY: docker.io
   # github.repository as <account>/<repo>
   IMAGE_NAME: ${{ github.repository }}
 
@@ -62,8 +62,8 @@ jobs:
       - name: Build and push Docker image
         uses: docker/build-push-action@3b5e8027fcad23fda98b2e3ac259d8d67585f671
         with:
-          context: ./bullseye
-          file: ./bullseye/Dockerfile
+          context: ./bookworm
+          file: ./bookworm/Dockerfile
           push: ${{ github.event_name != 'pull_request' }}
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}