Find UI doesn't work in Godot Documentation webview

### Godot version

4.4

### VS Code version

1.105.17075

### Godot Tools VS Code extension version

2.5.1

### System information

Debian Trixie (Linux)

### Issue description

I'm unable to search in Godot documentation using the usual Find UI that's built-in to VSC.

I am able to open and type into it with CTRL + F. However, even if I type words that I can clearly see are present in the webview, it returns no results.

I'd expect to be able to search for keywords in the documentation.

### Steps to reproduce

1. Invoke the **Godot Tools: List Godot classes** command.
2. Search something like **AnimationPlayer**.
3. Do CTRL + F. (This should open in the built-in Find UI.)
4. In the Find UI, search something like **animation**.
5. Observe that it has no results.