Introducing Xcode build for simulators

We've rolled out the beta version of a new step: Xcode build for simulators. This step will run the xcodebuild command with an iOS simulator destination and generate an .app file, which then can be run on a simulator. The step outputs include the generated app directory path, paths to dependent target apps, and the raw build results log file path. Building an iOS project to a simulator does not require codesigning the project, eliminating the need for certificates or provisioning profiles.