Empty doc tab appears, when Ctrl+clicking on undocumented identifier in GDscript editor

### Tested versions

Reproducible on 4.3.stable

### System information

Linux

### Issue description

It seems that this happens only for identifiers that are missing the documentation.
I'm not sure whether such classes should be even available through GDscript, but they're being hinted while writing the code.
When I try to use such class I get this error:
```
Native class GDScriptNativeClass used in script doesn't exist or isn't exposed.
```

Details in the attached video:

https://github.com/user-attachments/assets/ee2ef302-1186-4c4d-aa98-46ae63c5881a

### Steps to reproduce

1. Open any *.gd file
2. Start writing a code that uses an undocumented class (e.g. `MovieWriterMJPEG`)
3. Hold Ctrl key and click on it
4. Observe, that a new tab appeared, but it's content didn't open
5. Try to click on it to observe that an empty Docs window opens.

### Minimal reproduction project (MRP)

N/A