ci: Specify activity trigger type in ci events for merge queues (#1465)

Specify activity trigger type as checks_requested for merge_group ci
event. Currently this is the only supported activity type but this stops
us being surprised by unexpected triggers if they add more.

Author: abbiemery

.github/workflows/asyncapi.yml

@@ -9,6 +9,8 @@ on:
     tags:
       - '*'
   pull_request:
+  merge_group:
+    types: [checks_requested]
 
 jobs:
   validate:

.github/workflows/backstage.yml

@@ -7,6 +7,8 @@ on:
     tags:
       - '*'
   pull_request:
+  merge_group:
+    types: [checks_requested]
 
 jobs:
   validate:

.github/workflows/ci.yml

@@ -8,6 +8,7 @@ on:
       - "*"
   pull_request:
   merge_group:
+    types: [checks_requested]
 
 jobs:
   lint:

.github/workflows/codeql.yml

@@ -18,7 +18,8 @@ on:
     tags:
       - '*'
   pull_request:
-
+  merge_group:
+    types: [checks_requested]
 
 jobs:
   analyze:

.github/workflows/pr.yml

@@ -4,6 +4,7 @@ on:
   pull_request:
     types: [opened, synchronize, reopened, edited]
   merge_group:
+    types: [checks_requested]
 
 jobs:
   validate-pr-title: