### 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)


resolve_function_body(p_lambda->function, true);
	lambda_stack.pop_back();
	int captures_amount = p_lambda->captures.size();
	if (captures_amount > 0) {
		
		
		int param_count = p_lambda->function->parameters.size();
		p_lambda->function->parameters.resize(param_count + captures_amount);
		for (int i = param_count - 1; i >= 0; i--) {
			p_lambda->function->parameters.write[i + captures_amount] = p_lambda->function->parameters[i];
			p_lambda->function->parameters_indices[p_lambda->function->parameters[i]->identifier->name] = i + captures_amount;
		}
		
		for (int i = 0; i < p_lambda->captures.size(); i++) {
			GDScriptParser::IdentifierNode *capture = p_lambda->captures[i];
			GDScriptParser::ParameterNode *capture_param = parser->alloc_node<GDScriptParser::ParameterNode>();
			capture_param->identifier = capture;
			capture_param->usages = capture->usages;
			capture_param->set_datatype(capture->get_datatype());
			p_lambda->function->parameters.write[i] = capture_param;
			p_lambda->function->parameters_indices[capture->name] = i;
		}
	}
}
void GDScriptAnalyzer::reduce_literal(GDScriptParser::LiteralNode *p_literal) {
	p_literal->reduced_value = p_literal->value;
	p_literal->is_constant = true;
	p_literal->set_datatype(type_from_variant(p_literal->reduced_value, p_literal));
}
void GDScriptAnalyzer::reduce_preload(GDScriptParser::PreloadNode *p_preload) {