### 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 (base_class->has_member(name)) {
			parser->push_warning(p_local, GDScriptWarning::SHADOWED_VARIABLE, p_context, p_local->name, base_class->get_member(name).get_type_name(), itos(base_class->get_member(name).get_line()));
			return;
		}
		base_class = base_class->base_type.class_type;
	}
	StringName parent = base.native_type;
	while (parent != StringName()) {
		ERR_FAIL_COND_MSG(!class_exists(parent), "Non-existent native base class.");
		if (ClassDB::has_method(parent, name, true)) {
			parser->push_warning(p_local, GDScriptWarning::SHADOWED_VARIABLE_BASE_CLASS, p_context, p_local->name, "method", parent);
			return;
		} else if (ClassDB::has_signal(parent, name, true)) {
			parser->push_warning(p_local, GDScriptWarning::SHADOWED_VARIABLE_BASE_CLASS, p_context, p_local->name, "signal", parent);
			return;
		} else if (ClassDB::has_property(parent, name, true)) {
			parser->push_warning(p_local, GDScriptWarning::SHADOWED_VARIABLE_BASE_CLASS, p_context, p_local->name, "property", parent);
			return;
		} else if (ClassDB::has_integer_constant(parent, name, true)) {
			parser->push_warning(p_local, GDScriptWarning::SHADOWED_VARIABLE_BASE_CLASS, p_context, p_local->name, "constant", parent);
			return;
		} else if (ClassDB::has_enum(parent, name, true)) {
			parser->push_warning(p_local, GDScriptWarning::SHADOWED_VARIABLE_BASE_CLASS, p_context, p_local->name, "enum", parent);
			return;
		}
		parent = ClassDB::get_parent_class(parent);
	}
}
#endif
GDScriptParser::DataType GDScriptAnalyzer::get_operation_type(Variant::Operator p_operation, const GDScriptParser::DataType &p_a, bool &r_valid, const GDScriptParser::Node *p_source) {