ci: enable merge queue (#953)

* ci: enable merge queue

* ci: make sure we have a docker image tag for the merge queue

Author: rjaegers

.github/workflows/continuous-integration.yml

@@ -2,6 +2,7 @@
 name: Continuous Integration
 
 on:
+  merge_group:
   pull_request:
   push:
     branches: [main]

.github/workflows/linting-formatting.yml

@@ -2,6 +2,7 @@
 name: Linting & Formatting
 
 on:
+  merge_group:
   pull_request:
     types: [opened, synchronize, reopened]
   push:

.github/workflows/wc-build-push.yml

@@ -121,6 +121,7 @@ jobs:
           # Generate Docker tags based on the following events/attributes
           tags: |
             type=edge
+            type=raw,value=queue,enable=${{ github.event_name == 'merge_group' }}
             type=ref,event=pr
             type=semver,pattern={{raw}}
             type=semver,pattern={{version}}