Enabling Prefer Wayland editor setting on X11 prints errors to console on startup

### Tested versions

- Reproducible in: 4.3.dev cae759949

### System information

Godot v4.3.dev (cae759949) - Fedora Linux 39 (KDE Plasma) - X11 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 4090 (nvidia; 545.29.06) - 13th Gen Intel(R) Core(TM) i9-13900K (32 Threads)

### Issue description

Enabling Prefer Wayland editor setting on X11 prints errors to console on startup every time the editor starts.

Given the setting is phrased as *preferring* Wayland as opposed to requiring its use, I suggest silencing those errors or making them verbose-only.

```
ERROR: Can't connect to a Wayland display.
at: init (platform/linuxbsd/wayland/wayland_thread.cpp:3412)
ERROR: Could not initialize the Wayland thread.
at: DisplayServerWayland (platform/linuxbsd/wayland/display_server_wayland.cpp:1173)
ERROR: Can't create the Wayland display server.
at: create_func (platform/linuxbsd/wayland/display_server_wayland.cpp:1148)
```

### Steps to reproduce

Enable the **Prefer Wayland** editor setting then restart the editor on a X11 session while it's running in a terminal.

### Minimal reproduction project (MRP)

N/A

Start with the reported startup paths in platform/linuxbsd/wayland/wayland_thread.cpp and platform/linuxbsd/wayland/display_server_wayland.cpp, then trace how the Prefer Wayland editor setting is handled on an X11 session. Reproduce the restart from a terminal and confirm that Wayland fallback still works without printing the three errors.

Written by the indexing model from the issue text.