### Godot version

4.1.3

### System information

Linux

### Issue description

I'm trying to make an editor plugin on Rust:

```rust
#[derive(GodotClass)]
#[class(tool, editor_plugin, init, base=EditorPlugin)]
pub struct MyEditorPluginBase {}
```

But due to some limitations, I still have to use GDScript for some specific things.

So I tried to make a subclass of this Rust class:

```gdscript
@tool
class_name MyEditorPlugin
extends MyEditorPluginBase
```

This would work if `MyEditorPluginBase` was a GDScript class, but since it's a GDExtension class in my case, it doesn't work:

> Unable to load addon script from path: 'res://addons/my_addon/my_editor_plugin.gd' Base type is not EditorPlugin.

But it obviously **IS** EditorPlugin!

![godot-editorplugin-docs](https://github.com/godotengine/godot/assets/3236464/4665deeb-30f0-45cd-bfff-56101b9d4875)

![godot-editorplugin](https://github.com/godotengine/godot/assets/3236464/b1b6ecb4-de22-4abd-91a3-e180691f67ee)

If I understand correctly, this behavior is caused by this function, which checks some mysterious "instance base type" instead of real inheritance:

https://github.com/godotengine/godot/blob/fa4a65387ea41506ecc519fc61a06da110dce51c/editor/editor_node.cpp#L3456-L3458

https://github.com/godotengine/godot/blob/fa4a65387ea41506ecc519fc61a06da110dce51c/modules/gdscript/gdscript.cpp#L260-L263

Since the [documentation](https://docs.godotengine.org/en/stable/tutorials/plugins/editor/making_plugins.html#the-script-file) doesn't say that the script must be a **direct** subclass of EditorPlugin (and an indirect subclass works fine in GDScript), I interpret this behavior as a Godot bug.

### Steps to reproduce

See above

### Minimal reproduction project

[gdext_editor_plugin_test.zip](https://github.com/godotengine/godot/files/13451014/gdext_editor_plugin_test.zip)
#if DEBUG_ENABLED
	OS::get_singleton()->print("  --gpu-abort                       Abort on graphics API usage errors (usually validation layer errors). May help see the problem if your system freezes.\n");
#endif
	OS::get_singleton()->print("  --generate-spirv-debug-info       Generate SPIR-V debug information. This allows source-level shader debugging with RenderDoc.\n");
	OS::get_singleton()->print("  --remote-debug <uri>              Remote debug (<protocol>://<host/IP>[:<port>], e.g. tcp://127.0.0.1:6007).\n");
	OS::get_singleton()->print("  --single-threaded-scene           Scene tree runs in single-threaded mode. Sub-thread groups are disabled and run on the main thread.\n");
#if defined(DEBUG_ENABLED)
	OS::get_singleton()->print("  --debug-collisions                Show collision shapes when running the scene.\n");
	OS::get_singleton()->print("  --debug-paths                     Show path lines when running the scene.\n");
	OS::get_singleton()->print("  --debug-navigation                Show navigation polygons when running the scene.\n");
	OS::get_singleton()->print("  --debug-avoidance                 Show navigation avoidance debug visuals when running the scene.\n");
	OS::get_singleton()->print("  --debug-stringnames               Print all StringName allocations to stdout when the engine quits.\n");
	OS::get_singleton()->print("  --debug-canvas-item-redraw        Display a rectangle each time a canvas item requests a redraw (useful to troubleshoot low processor mode).\n");
#endif
	OS::get_singleton()->print("  --max-fps <fps>                   Set a maximum number of frames per second rendered (can be used to limit power usage). A value of 0 results in unlimited framerate.\n");
	OS::get_singleton()->print("  --frame-delay <ms>                Simulate high CPU load (delay each frame by <ms> milliseconds). Do not use as a FPS limiter; use --max-fps instead.\n");
	OS::get_singleton()->print("  --time-scale <scale>              Force time scale (higher values are faster, 1.0 is normal speed).\n");
	OS::get_singleton()->print("  --disable-vsync                   Forces disabling of vertical synchronization, even if enabled in the project settings. Does not override driver-level V-Sync enforcement.\n");
	OS::get_singleton()->print("  --disable-render-loop             Disable render loop so rendering only occurs when called explicitly from script.\n");
	OS::get_singleton()->print("  --disable-crash-handler           Disable crash handler when supported by the platform code.\n");
	OS::get_singleton()->print("  --fixed-fps <fps>                 Force a fixed number of frames per second. This setting disables real-time synchronization.\n");
	OS::get_singleton()->print("  --delta-smoothing <enable>        Enable or disable frame delta smoothing ['enable', 'disable'].\n");
	OS::get_singleton()->print("  --print-fps                       Print the frames per second to the stdout.\n");
	OS::get_singleton()->print("\n");
	OS::get_singleton()->print("Standalone tools:\n");
	OS::get_singleton()->print("  -s, --script <script>             Run a script.\n");
	OS::get_singleton()->print("  --main-loop <main_loop_name>      Run a MainLoop specified by its global class name.\n");
	OS::get_singleton()->print("  --check-only                      Only parse for errors and quit (use with --script).\n");
#ifdef TOOLS_ENABLED
	OS::get_singleton()->print("  --export-release <preset> <path>  Export the project in release mode using the given preset and output path. The preset name should match one defined in export_presets.cfg.\n");