### 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)


if (p_function->resolved_body) {
		return;
	}
	p_function->resolved_body = true;
#ifdef DEBUG_ENABLED
	HashSet<GDScriptWarning::Code> previously_ignored_warnings = parser->ignored_warnings;
	for (GDScriptWarning::Code ignored_warning : p_function->ignored_warnings) {
		parser->ignored_warnings.insert(ignored_warning);
	}
#endif
	GDScriptParser::FunctionNode *previous_function = parser->current_function;
	parser->current_function = p_function;
	bool previous_static_context = static_context;
	static_context = p_function->is_static;
	resolve_suite(p_function->body);
	if (!p_function->get_datatype().is_hard_type() && p_function->body->get_datatype().is_set()) {
		
		p_function->set_datatype(p_function->body->get_datatype());
	} else if (p_function->get_datatype().is_hard_type() && (p_function->get_datatype().kind != GDScriptParser::DataType::BUILTIN || p_function->get_datatype().builtin_type != Variant::NIL)) {
		if (!p_function->body->has_return && (p_is_lambda || p_function->identifier->name != GDScriptLanguage::get_singleton()->strings._init)) {
			push_error(R"(Not all code paths return a value.)", p_function);
		}
	}
#ifdef DEBUG_ENABLED
	parser->ignored_warnings = previously_ignored_warnings;
#endif
	parser->current_function = previous_function;
	static_context = previous_static_context;
}
void GDScriptAnalyzer::decide_suite_type(GDScriptParser::Node *p_suite, GDScriptParser::Node *p_statement) {