[release/3.1] Don't run Code Check in official builds

.azure/pipelines/ci.yml

@@ -89,27 +89,28 @@ stages:
   displayName: Build
   jobs:
   # Code check
-  - template: jobs/default-build.yml
-    parameters:
-      jobName: Code_check
-      jobDisplayName: Code check
-      agentOs: Windows
-      steps:
-      - ${{ if ne(variables['System.TeamProject'], 'public') }}:
-        - task: PowerShell@2
-          displayName: Setup Private Feeds Credentials
-          inputs:
-            filePath: $(Build.SourcesDirectory)/eng/common/SetupNugetSources.ps1
-            arguments: -ConfigFile $(Build.SourcesDirectory)/NuGet.config -Password $Env:Token
-          env:
-            Token: $(dn-bot-dnceng-artifact-feeds-rw)
-      - powershell: ./eng/scripts/CodeCheck.ps1 -ci $(_InternalRuntimeDownloadArgs)
-        displayName: Run eng/scripts/CodeCheck.ps1
-      artifacts:
-      - name: Code_Check_Logs
-        path: artifacts/log/
-        publishOnError: true
-        includeForks: true
+  - ${{ if or(eq(variables['System.TeamProject'], 'public'), in(variables['Build.Reason'], 'PullRequest')) }}:
+    - template: jobs/default-build.yml
+      parameters:
+        jobName: Code_check
+        jobDisplayName: Code check
+        agentOs: Windows
+        steps:
+        - ${{ if ne(variables['System.TeamProject'], 'public') }}:
+          - task: PowerShell@2
+            displayName: Setup Private Feeds Credentials
+            inputs:
+              filePath: $(Build.SourcesDirectory)/eng/common/SetupNugetSources.ps1
+              arguments: -ConfigFile $(Build.SourcesDirectory)/NuGet.config -Password $Env:Token
+            env:
+              Token: $(dn-bot-dnceng-artifact-feeds-rw)
+        - powershell: ./eng/scripts/CodeCheck.ps1 -ci $(_InternalRuntimeDownloadArgs)
+          displayName: Run eng/scripts/CodeCheck.ps1
+        artifacts:
+        - name: Code_Check_Logs
+          path: artifacts/log/
+          publishOnError: true
+          includeForks: true
 
   # Build Windows (x64/x86)
   - template: jobs/default-build.yml