fix: Use labeled event from pull request to trigger apps build (#2930)

.github/workflows/build-for-pr.yml

@@ -1,11 +1,9 @@
 name: build-for-pr
 
 on:
-  push:
-    # only for build-pr branches
-    # build-pr-*
-    branches:
-      - build-pr-*
+  pull_request:
+    types:
+      - labeled
 
 defaults:
   run:
@@ -17,9 +15,12 @@ env:
 jobs:
   build-linux-for-pr:
     runs-on: ubuntu-latest-4-cores
+    if: ${{ github.event.label.name == 'Build Apps for PR' }}
     steps:
       - name: ci/checkout-repo
         uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
       - name: ci/setup-node
         uses: actions/setup-node@64ed1c7eab4cce3362f8c340dee64e5eaeef8f7c # v3.6.0
         with:
@@ -49,9 +50,12 @@ jobs:
 
   windows-install-deps:
     runs-on: windows-2022
+    if: ${{ github.event.label.name == 'Build Apps for PR' }}
     steps:
       - name: ci/checkout-repo
         uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}        
       - name: ci/setup-node
         uses: actions/setup-node@64ed1c7eab4cce3362f8c340dee64e5eaeef8f7c # v3.6.0
         with:
@@ -76,11 +80,14 @@ jobs:
 
   build-win-for-pr:
     runs-on: windows-2022
+    if: ${{ github.event.label.name == 'Build Apps for PR' }}
     needs:
       - windows-install-deps
     steps:
       - name: ci/checkout-repo
         uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}        
       - name: ci/setup-node
         uses: actions/setup-node@64ed1c7eab4cce3362f8c340dee64e5eaeef8f7c # v3.6.0
         with:
@@ -130,9 +137,12 @@ jobs:
 
   build-mac-for-pr:
     runs-on: macos-12
+    if: ${{ github.event.label.name == 'Build Apps for PR' }}
     steps:
       - name: ci/checkout-repo
         uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}        
       - name: ci/setup-node
         uses: actions/setup-node@64ed1c7eab4cce3362f8c340dee64e5eaeef8f7c # v3.6.0
         with: