Calling AnimationPlayer.RootNode from C# errors in exported version

[poohcom1]

Godot version

4.2-dev6

System information

Windows 11

Issue description

Using the RootNode getter on AnimationPlayer from C# causes the following error in both debug and release exports.

ERROR: System.TypeInitializationException: The type initializer for 'Godot.AnimationMixer' threw an exception.
 ---> Godot.GodotObject+NativeMethodBindNotFoundException: Unable to find the native method bind. (Method 'AnimationMix)
   at Godot.GodotObject.ClassDB_get_method_with_compatibility(StringName type, StringName method, UInt64 hash)
   at Godot.AnimationMixer..cctor()
   --- End of inner exception stack trace ---
   at Godot.AnimationMixer.GetRootNode()
   at Godot.AnimationMixer.get_RootNode()
   at TestCSharp._Ready() in C:\Users\Pooh\Code\games\test-4.2dev6-animplayer\TestCSharp.cs:line 11
   at Godot.Node.InvokeGodotClassMethod(godot_string_name& method, NativeVariantPtrArgs args, godot_variant& ret)
   at Godot.CanvasItem.InvokeGodotClassMethod(godot_string_name& method, NativeVariantPtrArgs args, godot_variant& ret)
   at Godot.Node2D.InvokeGodotClassMethod(godot_string_name& method, NativeVariantPtrArgs args, godot_variant& ret)
   at TestCSharp.InvokeGodotClassMethod(godot_string_name& method, NativeVariantPtrArgs args, godot_variant& ret) in C:8
   at Godot.Bridge.CSharpInstanceBridge.Call(IntPtr godotObjectGCHandle, godot_string_name* method, godot_variant** arg)
   at: void Godot.NativeInterop.ExceptionUtils.LogException(System.Exception) (:0)

The code runs fine in the editor and the same issue does not happen with GDScript.

Steps to reproduce

From scratch:

1. Create a C# script that references an AnimationPlayer.
2. Call AnimationPlayer.RootNode.
3. Create a debug or release export.
4. Run the export with console.
5. The scene will show a "GDScript" label, but not the "CSharp" label because the CSharp script errored.
6. Check the console output for the error message.

With the MRP:

1. Create an export.
2. Run the export with console.
3. Same steps as above.

Minimal reproduction project

dotnet-getrootnode-mrp.zip

[raulsntos]

It seems #80813 introduced methods that are only bound when running in/from the editor:

godot/scene/animation/animation_mixer.cpp

Lines 2075 to 2082 in 6916349

	#ifdef TOOLS_ENABLED
	ClassDB::bind_method(D_METHOD("_reset"), &AnimationMixer::reset);
	ClassDB::bind_method(D_METHOD("_restore", "backup"), &AnimationMixer::restore);
	ClassDB::bind_method(D_METHOD("set_reset_on_save_enabled", "enabled"), &AnimationMixer::set_reset_on_save_enabled);
	ClassDB::bind_method(D_METHOD("is_reset_on_save_enabled"), &AnimationMixer::is_reset_on_save_enabled);
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "reset_on_save", PROPERTY_HINT_NONE, ""), "set_reset_on_save_enabled", "is_reset_on_save_enabled");
	ADD_SIGNAL(MethodInfo("mixer_updated")); // For updating dummy player.
	#endif // TOOLS_ENABLED

I think this is the same as #72864. This was fixed by moving the #ifdef DEBUG_ENABLED to the methods implementation (#72922) so maybe we should do something similar here.

cc @TokageItLab