Go to Symbol in Workspace... shows empty list with "No matching workspace symbols"

### Godot version

v4.6.stable.official [89cea1439]

### VS Code version

1.109.5

### Godot Tools VS Code extension version

2.6.1

### System information

Windows 11

### Issue description

Go to Symbol in Workspace... (Ctrl+T) (search with prefix `#`) doesn't have any match wherever I search from. Typing anything will show message "No matching workspace symbols":

Note: Go to Symbol in Editor... (Ctrl+Shift+O) (search with prefix `@`) works, but it only shows a list of symbols in the current file. Looking at how it's called "Go to Symbol in File" in some doc (https://code.visualstudio.com/docs/languages/go), I suspect it's the intended behavior. No idea why they renamed it "in Editor" and "editor symbols" in the "No matching editor symbols" message, it's confusing.

Remark: the issue has been already reported in a comment in [#157](https://github.com/godotengine/godot-vscode-plugin/issues/157#issuecomment-3594576256) but since it was a different bug that was closed I opened a new one.

### Steps to reproduce

1. Open Godot project
2. Open project folder in VS Code
3. Ctrl+T to Go to Symbol in Workspace... => list is empty
4. Type anything => "No matching workspace symbols"