Added check for forked branches (#20720)

Co-authored-by: Evgenii Dergachev <[email protected]>

Author: DmitriiBobreshev

Diff for: ci/build-all-steps.yml

@@ -29,6 +29,12 @@ steps:
 - script: npm install
   displayName: npm install
 
+- script: |
+    echo "##[error]PRs from fork repositories forbidden. Create PR directly."
+    exit 1
+  displayName: Check Is Forked PR
+  condition: eq(variables['SYSTEM.PULLREQUEST.ISFORK'], 'true')
+
 # Verify min agent demands
 - script: |
     cd ci/verifyMinAgentDemands