### 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)


case GDScriptParser::PatternNode::PT_DICTIONARY:
			for (int i = 0; i < p_match_pattern->dictionary.size(); i++) {
				if (p_match_pattern->dictionary[i].key) {
					reduce_expression(p_match_pattern->dictionary[i].key);
					if (!p_match_pattern->dictionary[i].key->is_constant) {
						push_error(R"(Expression in dictionary pattern key must be a constant.)", p_match_pattern->dictionary[i].key);
					}
				}
				if (p_match_pattern->dictionary[i].value_pattern) {
					resolve_match_pattern(p_match_pattern->dictionary[i].value_pattern, nullptr);
					decide_suite_type(p_match_pattern, p_match_pattern->dictionary[i].value_pattern);
				}
			}
			result = p_match_pattern->get_datatype();
			break;
		case GDScriptParser::PatternNode::PT_WILDCARD:
		case GDScriptParser::PatternNode::PT_REST:
			result.kind = GDScriptParser::DataType::VARIANT;
			break;
	}
	p_match_pattern->set_datatype(result);
}
void GDScriptAnalyzer::resolve_return(GDScriptParser::ReturnNode *p_return) {
	GDScriptParser::DataType result;
	GDScriptParser::DataType expected_type;
	bool has_expected_type = parser->current_function != nullptr;
	if (has_expected_type) {
		expected_type = parser->current_function->get_datatype();
	}
	if (p_return->return_value != nullptr) {