Fix 'dspacesolr' build issues in GitHub actions by adding 'solrconfig' as an additional_context

.github/workflows/docker.yml

@@ -102,6 +102,8 @@ jobs:
       build_id: dspace-solr
       image_name: dspace/dspace-solr
       dockerfile_path: ./dspace/src/main/docker/dspace-solr/Dockerfile
+      # Must pass solrconfigs to the Dockerfile so that it can find the required Solr config files
+      dockerfile_additional_contexts: 'solrconfigs=./dspace/solr/'
     secrets:
       DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
       DOCKER_ACCESS_TOKEN: ${{ secrets.DOCKER_ACCESS_TOKEN }}

.github/workflows/reusable-docker-build.yml

@@ -24,6 +24,12 @@ on:
       dockerfile_context:
         required: false
         type: string
+        default: '.'
+      # Optionally a list of "additional_contexts" to pass to Dockerfile. Defaults to empty
+      dockerfile_additional_contexts:
+        required: false
+        type: string
+        default: ''
       # If Docker image should have additional tag flavor details (e.g. a suffix), it may be passed in.
       tags_flavor:
         required: false
@@ -123,7 +129,9 @@ jobs:
         id: docker_build
         uses: docker/build-push-action@v5
         with:
-          context: ${{ inputs.dockerfile_context || '.' }}
+          build-contexts: |
+            ${{ inputs.dockerfile_additional_contexts }}
+          context: ${{ inputs.dockerfile_context }}
           file: ${{ inputs.dockerfile_path }}
           platforms: ${{ matrix.arch }}
           # For pull requests, we run the Docker build (to ensure no PR changes break the build),