### Preflight Checklist

- [X] I have read the [Contributing Guidelines](https://github.com/electron/electron/blob/master/CONTRIBUTING.md) for this project.
- [X] I agree to follow the [Code of Conduct](https://github.com/electron/electron/blob/master/CODE_OF_CONDUCT.md) that this project adheres to.
- [X] I have searched the [issue tracker](https://www.github.com/electron/electron/issues) for a feature request that matches the one I want to file, without success.

### Electron Version

12.0.1

### What operating system are you using?

macOS

### Operating System Version

11.2

### What arch are you using?

x64

### Last Known Working Electron version

_No response_

### Expected Behavior

`error.message` shouldn't be prefixed with "Uncaught Error:"

### Actual Behavior

`error.message` is prefixed with "Uncaught Error:" when an error is thrown in a function defined in the preload script and caught in the renderer process. This only happens when `contextIsolation` is enabled.

### Testcase Gist URL

https://gist.github.com/f11c77f9bc2cbf98d42a9fcaf477c80a


shell/renderer/api/electron_api_context_bridge.cc
const std::vector<std::string>& key_path,
    v8::Local<v8::Object> getter,
    v8::Local<v8::Value> setter,
    gin_helper::Arguments* args) {
  if (key_path.empty())
    return false;
  auto* render_frame = GetRenderFrame(getter);
  CHECK(render_frame);
  auto* frame = render_frame->GetWebFrame();
  CHECK(frame);
  v8::Local<v8::Context> main_context = frame->MainWorldScriptContext();
  gin_helper::Dictionary global(main_context->GetIsolate(),
                                main_context->Global());