### 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)


for (int i = 0; i < p_array->elements.size(); i++) {
		GDScriptParser::ExpressionNode *element_node = p_array->elements[i];
		if (element_node->is_constant) {
			update_const_expression_builtin_type(element_node, p_element_type, "include");
		}
		const GDScriptParser::DataType &element_type = element_node->get_datatype();
		if (element_type.has_no_type() || element_type.is_variant() || !element_type.is_hard_type()) {
			mark_node_unsafe(element_node);
			continue;
		}
		if (!is_type_compatible(p_element_type, element_type, true, p_array)) {
			if (is_type_compatible(element_type, p_element_type)) {
				mark_node_unsafe(element_node);
				continue;
			}
			push_error(vformat(R"(Cannot have an element of type "%s" in an array of type "Array[%s]".)", element_type.to_string(), p_element_type.to_string()), element_node);
			return;
		}
	}
	GDScriptParser::DataType array_type = p_array->get_datatype();
	array_type.set_container_element_type(p_element_type);
	p_array->set_datatype(array_type);
}
void GDScriptAnalyzer::reduce_assignment(GDScriptParser::AssignmentNode *p_assignment) {