### Godot version

4.1.beta3

### System information

Fedora Workstation 38 - Godot 4.1.beta3 - Vulkan (Forward+)

### Issue description

**This is an issue created by the production team, we're working on it**

Currently, it's impossible to call virtual functions within GDScript.

This currently returns an error:
```gdscript
# a.gd
extends Node

func _process(delta: float) -> void:
	pass
```

```gdscript
# main.gd
extends Node

var my_node: Node = preload("res://a.gd").new()

func _process(delta: float) -> void:
	my_node._process(delta)  # Cannot call virtual function "_process()" because it hasn't been defined.
```

### Steps to reproduce

1. Create a script (`a.gd`) based on `Node` that declares `_process()`;
2. Create a main node;
3. Attach a script to the main node;
4. Initialize a variable with a new `a.gd` instance;
5. Try to run `_process()` on that node;
6. Find out that it returns an error.

### Minimal reproduction project

[virtual_functions.zip (updated)](https://github.com/godotengine/godot/files/11823992/virtual_functions.zip)


}
					j++;
				}
				parent_signature += ") -> ";
				const String return_type = parent_return_type.is_hard_type() ? parent_return_type.to_string() : "Variant";
				if (return_type == "null") {
					parent_signature += "void";
				} else {
					parent_signature += return_type;
				}
				push_error(vformat(R"(The function signature doesn't match the parent. Parent signature is "%s".)", parent_signature), p_function);
			}
#ifdef DEBUG_ENABLED
			if (native_base != StringName()) {
				parser->push_warning(p_function, GDScriptWarning::NATIVE_METHOD_OVERRIDE, function_name, native_base);
			}
#endif
		}
#endif 
	}
	if (p_function->get_datatype().is_resolving()) {
		p_function->set_datatype(prev_datatype);
	}
#ifdef DEBUG_ENABLED
	parser->ignored_warnings = previously_ignored_warnings;
#endif
	parser->current_function = previous_function;
	static_context = previous_static_context;
}
void GDScriptAnalyzer::resolve_function_body(GDScriptParser::FunctionNode *p_function, bool p_is_lambda) {