### Godot version

4.0.beta10.mono.official

### System information

Windows 11

### Issue description

After registering a C# Script with Autoload and trying to connect to a signal using the `Signal.connect` method (`Singleton.Signal.connect(xxx)`) fails with `Invalid get index 'Signal' (on base: 'Node (Singleton.cs)'). But with `Object.connect` it works.

### Steps to reproduce

- Create a C# class script with a Signal named `Signal` (could be any other).
- Register it with Autoload with the name `Singleton` (could be any other).
- Create a GDScript script and try to connect the Singleton's signal using `Singleton.Signal.connect(xxx)`
- When running the project it fails with `Invalid get index 'Sample' (on base: 'Node (Singleton.cs)').`

### Minimal reproduction project

[example.zip](https://github.com/godotengine/godot/files/10414500/example.zip)

ERR_FAIL_COND_V_MSG(arg_type->is_singleton, ERR_BUG,
				"Argument type is a singleton: '" + iarg.name + "' of method '" + p_itype.name + "." + p_imethod.name + "'.");
		if (p_itype.api_type == ClassDB::API_CORE) {
			ERR_FAIL_COND_V_MSG(arg_type->api_type == ClassDB::API_EDITOR, ERR_BUG,
					"Argument '" + iarg.name + "' of method '" + p_itype.name + "." + p_imethod.name + "' has type '" +
							arg_type->name + "' from the editor API. Core API cannot have dependencies on the editor API.");
		}
		if (iarg.default_argument.size()) {
			CRASH_COND_MSG(!_arg_default_value_is_assignable_to_type(iarg.def_param_value, *arg_type),
					"Invalid default value for parameter '" + iarg.name + "' of method '" + p_itype.name + "." + p_imethod.name + "'.");
		}
		String arg_cs_type = arg_type->cs_type + _get_generic_type_parameters(*arg_type, iarg.type.generic_type_parameters);
		
		
		{
			if (&iarg != &first) {
				arguments_sig += ", ";
			}
			if (iarg.def_param_mode == ArgumentInterface::NULLABLE_VAL) {
				arguments_sig += "Nullable<";
			}
			arguments_sig += arg_cs_type;
			if (iarg.def_param_mode == ArgumentInterface::NULLABLE_VAL) {
				arguments_sig += "> ";
			} else {
				arguments_sig += " ";
			}
			arguments_sig += iarg.name;
			if (iarg.default_argument.size()) {
				if (iarg.def_param_mode != ArgumentInterface::CONSTANT) {