Seperates out the library image building into a new, minimal workflow

.github/workflows/ci.yml

@@ -57,6 +57,12 @@ jobs:
     name: Prepare Docker Pipeline Data
     if: github.event_name == 'push' && (startsWith(github.ref, 'refs/heads/feature-') || github.ref == 'refs/heads/dev' || github.ref == 'refs/heads/beta' || contains(github.ref, 'beta.rc') || startsWith(github.ref, 'refs/tags/v'))
     runs-on: ubuntu-20.04
+    # If the push triggered the installer library workflow, wait for it to
+    # complete here.  This ensures the required versions for the final
+    # image have been built, while not waiting at all if the versions haven't changed
+    concurrency:
+      group: build-installer-library
+      cancel-in-progress: false
     needs:
       - documentation
       - ci-backend
@@ -117,55 +123,6 @@ jobs:
 
       jbig2enc-json: ${{ steps.jbig2enc-setup.outputs.jbig2enc-json}}
 
-  build-qpdf-debs:
-    name: qpdf
-    needs:
-      - prepare-docker-build
-    uses: ./.github/workflows/reusable-workflow-builder.yml
-    with:
-      dockerfile: ./docker-builders/Dockerfile.qpdf
-      build-json: ${{ needs.prepare-docker-build.outputs.qpdf-json }}
-      build-args: |
-        QPDF_VERSION=${{ fromJSON(needs.prepare-docker-build.outputs.qpdf-json).version }}
-
-  build-jbig2enc:
-    name: jbig2enc
-    needs:
-      - prepare-docker-build
-    uses: ./.github/workflows/reusable-workflow-builder.yml
-    with:
-      dockerfile: ./docker-builders/Dockerfile.jbig2enc
-      build-json: ${{ needs.prepare-docker-build.outputs.jbig2enc-json }}
-      build-args: |
-        JBIG2ENC_VERSION=${{ fromJSON(needs.prepare-docker-build.outputs.jbig2enc-json).version }}
-
-  build-psycopg2-wheel:
-    name: psycopg2
-    needs:
-      - prepare-docker-build
-    uses: ./.github/workflows/reusable-workflow-builder.yml
-    with:
-      dockerfile: ./docker-builders/Dockerfile.psycopg2
-      build-json: ${{ needs.prepare-docker-build.outputs.psycopg2-json }}
-      build-args: |
-        PSYCOPG2_GIT_TAG=${{ fromJSON(needs.prepare-docker-build.outputs.psycopg2-json).git_tag }}
-        PSYCOPG2_VERSION=${{ fromJSON(needs.prepare-docker-build.outputs.psycopg2-json).version }}
-
-  build-pikepdf-wheel:
-    name: pikepdf
-    needs:
-      - prepare-docker-build
-      - build-qpdf-debs
-    uses: ./.github/workflows/reusable-workflow-builder.yml
-    with:
-      dockerfile: ./docker-builders/Dockerfile.pikepdf
-      build-json: ${{ needs.prepare-docker-build.outputs.pikepdf-json }}
-      build-args: |
-        REPO=${{ github.repository }}
-        QPDF_VERSION=${{ fromJSON(needs.prepare-docker-build.outputs.qpdf-json).version }}
-        PIKEPDF_GIT_TAG=${{ fromJSON(needs.prepare-docker-build.outputs.pikepdf-json).git_tag }}
-        PIKEPDF_VERSION=${{ fromJSON(needs.prepare-docker-build.outputs.pikepdf-json).version }}
-
   # build and push image to docker hub.
   build-docker-image:
     runs-on: ubuntu-20.04
@@ -174,10 +131,6 @@ jobs:
       cancel-in-progress: true
     needs:
       - prepare-docker-build
-      - build-psycopg2-wheel
-      - build-jbig2enc
-      - build-qpdf-debs
-      - build-pikepdf-wheel
     steps:
       -
         name: Check pushing to Docker Hub