### 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)


Variant value;
	if (p_expression == nullptr) {
		return value;
	}
	if (p_expression->is_constant) {
		is_reduced = true;
		value = p_expression->reduced_value;
	} else if (p_expression->type == GDScriptParser::Node::ARRAY) {
		value = make_array_reduced_value(static_cast<GDScriptParser::ArrayNode *>(p_expression), is_reduced);
	} else if (p_expression->type == GDScriptParser::Node::DICTIONARY) {
		value = make_dictionary_reduced_value(static_cast<GDScriptParser::DictionaryNode *>(p_expression), is_reduced);
	} else if (p_expression->type == GDScriptParser::Node::SUBSCRIPT) {
		value = make_subscript_reduced_value(static_cast<GDScriptParser::SubscriptNode *>(p_expression), is_reduced);
	}
	return value;
}
Variant GDScriptAnalyzer::make_array_reduced_value(GDScriptParser::ArrayNode *p_array, bool &is_reduced) {