Large cursor over some flatpak apps

### What Happened?

The cursor becomes noticeably larger when it enters a [Loupe](https://flathub.org/en/apps/org.gnome.Loupe) window, for example.

https://github.com/user-attachments/assets/9be4f0eb-1a1f-401a-a1d9-c9faf66577a2

~Because this is the only app showing this behavior,~ I first reported it to the [Loupe bug tracker](https://gitlab.gnome.org/GNOME/loupe/-/issues/554); but they replied this:

> I don't see how this can be a Loupe issue. Elementar OS 8 uses mutter 45 afaik. Our current version is 49. And there has been a lot of work around cursors. So I would suggest to report it there first.

### Steps to Reproduce

1. Install [Loupe from Flathub](https://flathub.org/en/apps/org.gnome.Loupe).
2. Run it, and observe the cursor as you interact with its window.

### Expected Behavior

Cursor size should be consistent with the configuration.

### OS Version

8.x (Circe)

### OS Architecture

amd64 (on most hardwares)

### Session Type

Secure Session (Wayland, This is the default)

### Software Version

Latest release (I have run all updates)

### Log Output

```shell

```

### Hardware Info

_No response_