### 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_expression(p_assert->condition);
	if (p_assert->message != nullptr) {
		reduce_expression(p_assert->message);
		if (!p_assert->message->get_datatype().has_no_type() && (p_assert->message->get_datatype().kind != GDScriptParser::DataType::BUILTIN || p_assert->message->get_datatype().builtin_type != Variant::STRING)) {
			push_error(R"(Expected string for assert error message.)", p_assert->message);
		}
	}
	p_assert->set_datatype(p_assert->condition->get_datatype());
#ifdef DEBUG_ENABLED
	if (p_assert->condition->is_constant) {
		if (p_assert->condition->reduced_value.booleanize()) {
			parser->push_warning(p_assert->condition, GDScriptWarning::ASSERT_ALWAYS_TRUE);
		} else if (!(p_assert->condition->type == GDScriptParser::Node::LITERAL && static_cast<GDScriptParser::LiteralNode *>(p_assert->condition)->value.get_type() == Variant::BOOL)) {
			parser->push_warning(p_assert->condition, GDScriptWarning::ASSERT_ALWAYS_FALSE);
		}
	}
#endif
}
void GDScriptAnalyzer::resolve_match(GDScriptParser::MatchNode *p_match) {
	reduce_expression(p_match->test);
	for (int i = 0; i < p_match->branches.size(); i++) {
		resolve_match_branch(p_match->branches[i], p_match->test);
		decide_suite_type(p_match, p_match->branches[i]);
	}
}
void GDScriptAnalyzer::resolve_match_branch(GDScriptParser::MatchBranchNode *p_match_branch, GDScriptParser::ExpressionNode *p_match_test) {