Hot Reloading doesn't work when built with CMake

[ytnuf]

Godot version

4.2

godot-cpp version

4.2

System information

Fedora Linux 40

Issue description

If you build godot-cpp with CMake and use it for a GDExtension project, said project will not support hot reloading. Even if you specify the reloadable=true in the gdextension file.

Steps to reproduce

• Obtain a GDExtension project that uses CMake (a simple to reproduce example is provided below)
• Build the library
• Open a godot project that uses the library (also included below)
• Edit one file, and rebuild the library
• Go back to godot, and an error will appear ("Unable to recreate GDExtension instance - does this extension support hot reloading?")

Minimal reproduction project

https://github.com/ytnuf/gdextension_example

[Klaim]

Indeed, one needs to add -DHOT_RELOAD_ENABLED to the CMake configuration to enable it (this is an immediate workaround you can use if you need to now) but no explicit options are currently setup for CMake, nor is it documented (or I just didnt find it?).