Node Search does not update context menu position if the content is identical

### Tested versions

- Reproducible in: 4.6.stable (see below for details on 4.5.1)

### System information

Godot v4.6.stable - Ubuntu 24.04.4 LTS 24.04 on X11 - X11 display driver, Multi-window, 2 monitors - OpenGL 3 (Compatibility) - AMD Radeon 760M Graphics (radeonsi, phoenix, LLVM 20.1.2, DRM 3.57, 6.8.0-100-generic) - AMD Ryzen 5 7640U w/ Radeon 760M Graphics (12 threads) - 13.45 GiB memory

### Issue description

In the node search, the context menu position of the icons on the right (experimental/deprecated) is not updated if you hover over an identical icon on another line. (also affects 4.5.1)

There is also a bug where the context menu does not update/hide until the mouse leaves the `Matches` field but I cannot reproduce that one reliably yet. You know you triggered it once the hovered line does not update any more. Probably got something to do with how long you hover, maybe also how many times you triggered the first part above. I seem to get it after a bit if `NavigationLink2D` is selected, then hovering over NavigationRegion2D` and then just moving between the marks. (could not reproduce in 4.5.1, so might be a regression)

The issues are reset when you re-open the window.

As a side note, would reserving space on the right for the marks be considered? Could open a proposal for that.

### Steps to reproduce

- Search for a Node, e.g. under `Node2D`
- `NavigationLink2D`, `NavigationObstacle2D`, `NavigationRegion2D` are listed back to back, all of them are marked as experimental
- Hover over a mark, then hover over another one

### Minimal reproduction project (MRP)

N/A