### 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)


reduce_unary_op(static_cast<GDScriptParser::UnaryOpNode *>(p_expression));
			break;
		
		case GDScriptParser::Node::NONE:
		case GDScriptParser::Node::ANNOTATION:
		case GDScriptParser::Node::ASSERT:
		case GDScriptParser::Node::BREAK:
		case GDScriptParser::Node::BREAKPOINT:
		case GDScriptParser::Node::CLASS:
		case GDScriptParser::Node::CONSTANT:
		case GDScriptParser::Node::CONTINUE:
		case GDScriptParser::Node::ENUM:
		case GDScriptParser::Node::FOR:
		case GDScriptParser::Node::FUNCTION:
		case GDScriptParser::Node::IF:
		case GDScriptParser::Node::MATCH:
		case GDScriptParser::Node::MATCH_BRANCH:
		case GDScriptParser::Node::PARAMETER:
		case GDScriptParser::Node::PASS:
		case GDScriptParser::Node::PATTERN:
		case GDScriptParser::Node::RETURN:
		case GDScriptParser::Node::SIGNAL:
		case GDScriptParser::Node::SUITE:
		case GDScriptParser::Node::TYPE:
		case GDScriptParser::Node::VARIABLE:
		case GDScriptParser::Node::WHILE:
			ERR_FAIL_MSG("Reaching unreachable case");
	}
}
void GDScriptAnalyzer::reduce_array(GDScriptParser::ArrayNode *p_array) {