build: [upgrade-makesystem-bot] Upgrade to v0.5.27.

Automated change generated by the Upgrade Makesystem Bot.

.bootstrap/VERSION

@@ -1 +1 @@
-0.5.26
+0.5.27

.github/workflows/build.yml

@@ -21,6 +21,7 @@ on:
 
 permissions:
   contents: read
+  packages: write
 
 env:
   PLATFORMS: linux/amd64,linux/arm64/v8
@@ -101,6 +102,13 @@ jobs:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
       - name: Build amd64 Docker image locally
         uses: docker/build-push-action@v5
         with:
@@ -115,7 +123,7 @@ jobs:
         run: |
           IMAGE_TAG=${{ env.DOCKERHUB_TEST_TAG }} make test
 
-      - name: Build docker images for all platforms (with registry push)
+      - name: Build docker images for all platforms (with registry pushes)
         uses: docker/build-push-action@v5
         if: >-
           (
@@ -128,11 +136,13 @@ jobs:
           context: .
           platforms: ${{env.PLATFORMS}}
           push: true
-          tags: ${{ env.DOCKERHUB_REPO_NAME }}:${{ env.DOCKERHUB_PUBLISH_TAG }}
+          tags: |
+            ${{ env.DOCKERHUB_REPO_NAME }}:${{ env.DOCKERHUB_PUBLISH_TAG }}
+            ${{ env.GHCR_REPO_NAME }}:${{ env.DOCKERHUB_PUBLISH_TAG }}
           build-args: ${{ steps.docker_build_args.outputs.build_args }}
           allow: ${{ steps.docker_entitlements.outputs.entitlements }}
 
-      - name: Build docker images for all platforms (no registry push)
+      - name: Build docker images for all platforms (no registry pushes)
         uses: docker/build-push-action@v5
         if: >-
           (