Can no longer step into methods exposed via contextBridge

### Preflight Checklist

- [x] I have read the [Contributing Guidelines](https://github.com/electron/electron/blob/main/CONTRIBUTING.md) for this project.
- [x] I agree to follow the [Code of Conduct](https://github.com/electron/electron/blob/main/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 bug report that matches the one I want to file, without success.

### Electron Version

34.0.2

### What operating system(s) are you using?

Windows

### Operating System Version

Windows 11 Version 24H2 (Os Build 26100.2894)

### What arch are you using?

x64

### Last Known Working Electron version

33.32

### Expected Behavior

I expect to be able to step into functions that I expose via `contextBridge.exposeInMainWorld`

### Actual Behavior

As of the latest stable version, I can no longer do this.

This isn't particularly important to me, but reporting in case this was an unintentional change.

### Testcase Gist URL

https://gist.github.com/pushkin-/5b542e02e6ddbd130124cd6ea270f499

### Additional Information

1. start app
3. In devtools, press ctrl+p to open renderer.js and set a breakpoint at `__apis.foo()`
4. Click the "Click" button
5. Press F11 to step into the code. This doesn't work anymore.