infra(CI): prepare CI for GitHub merge queues (#3245)

.github/workflows/check-mergable-by-label.yml

@@ -9,6 +9,7 @@ on:
       - edited
       - labeled
       - unlabeled
+  merge_group:
 
 permissions: {}
 

.github/workflows/ci.yml

@@ -5,6 +5,7 @@ on:
     branches:
       - next
   pull_request:
+  merge_group:
 
 permissions:
   contents: read # to fetch code (actions/checkout)

.github/workflows/pr.yml

@@ -2,6 +2,7 @@ name: PR
 
 on:
   pull_request:
+  merge_group:
 
 permissions:
   contents: read # to fetch code (actions/checkout)

.github/workflows/semantic-pull-request.yml

@@ -6,6 +6,7 @@ on:
       - opened
       - edited
       - synchronize
+  merge_group:
 
 permissions: {}