C#: Modifying C# scripts in editor crashes the running project.

[zaevi]

Tested versions

• Reproducible in v4.3.dev.mono.custom_build [63d6bda] - after GDScript: Hot-reload changed scripts only #86676
• Not reproducible in 4.2.1.stable

System information

Godot v4.3.dev.mono (63d6bda) - Windows 10.0.22621 - Vulkan (Mobile) - dedicated NVIDIA GeForce RTX 2050 () - 12th Gen Intel(R) Core(TM) i5-12500H (16 Threads)

Issue description

It looks like #86676 also try hot-reloading for C# when debugging, but C# doesn't support that yet.

ERROR: FATAL: Condition "!Engine::get_singleton()->is_editor_hint()" is true.
   at: CSharpLanguage::reload_scripts (modules\mono\csharp_script.cpp:730)

================================================================
CrashHandlerException: Program crashed
Engine version: Godot Engine v4.3.dev.mono.custom_build (63d6bda8e95ac992da74e84b2f3be62f3d85190b)
Dumping the backtrace. Please include this when reporting the bug to the project developer.
[0] CSharpLanguage::reload_scripts (C:\Users\zaevi\source\Godot\godot-source\modules\mono\csharp_script.cpp:730)
[1] CSharpLanguage::reload_scripts (C:\Users\zaevi\source\Godot\godot-source\modules\mono\csharp_script.cpp:730)
[2] RemoteDebugger::poll_events (C:\Users\zaevi\source\Godot\godot-source\core\debugger\remote_debugger.cpp:611)
[3] Main::iteration (C:\Users\zaevi\source\Godot\godot-source\main\main.cpp:3974)
[4] OS_Windows::run (C:\Users\zaevi\source\Godot\godot-source\platform\windows\os_windows.cpp:1476)
[5] widechar_main (C:\Users\zaevi\source\Godot\godot-source\platform\windows\godot_windows.cpp:182)
[6] _main (C:\Users\zaevi\source\Godot\godot-source\platform\windows\godot_windows.cpp:206)
[7] main (C:\Users\zaevi\source\Godot\godot-source\platform\windows\godot_windows.cpp:218)
[8] __scrt_common_main_seh (D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288)
[9] <couldn't map PC to fn name>
-- END OF BACKTRACE --
================================================================

Steps to reproduce

1. Create a scene with C# script.
2. Run the scene.
3. When running, modify the C# script, and save.

Minimal reproduction project (MRP)

N/A