Cleanup from install_xcode refactoring

Bug: 1055330
Change-Id: I5b6adc215b87f4fee4652e22f71d32d5c62d6a5b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2078732Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Commit-Queue: Jeff Yoon <jeffyoon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#745244}

ios/build/bots/scripts/run.py

@@ -192,7 +192,6 @@ class Runner():
       else:
         tr = test_runner.DeviceTestRunner(
             self.args.app,
-            self.args.xcode_build_version,
             self.args.out_dir,
             env_vars=self.args.env_var,
             restart=self.args.restart,