fix: correct DEVELOPER_DIR path and ensure proper environment variable usage in iOS harness workflow

Author: YogendraShelke

.github/workflows/test-ios-harness.yml

@@ -7,14 +7,15 @@ env:
   DEVICE_MODEL: 'iPhone 17 Pro'
   IOS_VERSION: '26.0'
   USE_CCACHE: 1
-  DEVELOPER_DIR: /Applications/Xcode_26.1.0.app/Contents/Developer
+  DEVELOPER_DIR: /Applications/Xcode_26.1.app/Contents/Developer
+
 jobs:
   test-ios-harness:
     name: Test iOS Harness
     runs-on: macos-latest
     timeout-minutes: 60
     env:
-      DEVELOPER_DIR: env.DEVELOPER_DIR
+      DEVELOPER_DIR: ${{ env.DEVELOPER_DIR }}
 
     steps:
       - name: Checkout