### Godot version

v4.0.beta15.official [4fa6edc88]

### System information

Windows 10 (10.0.19045 Build 19045) | Forward+ | Vulkan API 1.3.206 | AMD Radeon RX 6800 XT

### Issue description

If there is a function with arguments within a `.gdshaderinc` file, then this function can not be used in other shaders that include this via a relative include. The error in the other shaders is "Too many arguments for "example()" call. Expected at most 0 but received 1". Using an absolute path for the include resolves the error.

**Note:** The relative include *does* work in the special case of both files being in the project root.

### Steps to reproduce

1. Put a shader and a shader-include file into a subdirectory
2. Write a function with arguments in the shader-include file
3. Include that file in the shader
4. Try to use the function

### Minimal reproduction project

[shader-include-bug.zip](https://github.com/godotengine/godot/files/10508745/shader-include-bug.zip)

}
	Variant v = expression.execute(Array(), nullptr, false);
	if (v.get_type() == Variant::NIL) {
		set_error(RTR("Condition evaluation error."), line);
		return;
	}
	bool success = v.booleanize();
	start_branch_condition(p_tokenizer, success);
	if (state->save_regions) {
		add_region(line + 1, success, state->previous_region);
	}
}
void ShaderPreprocessor::process_ifdef(Tokenizer *p_tokenizer) {
	const int line = p_tokenizer->get_line();
	String label = p_tokenizer->get_identifier();
	if (label.is_empty()) {
		set_error(RTR("Invalid macro name."), line);
		return;
	}
	if (!p_tokenizer->consume_empty_line()) {
		set_error(RTR("Invalid ifdef."), line);
		return;
	}
	bool success = state->defines.has(label);
	start_branch_condition(p_tokenizer, success);
	if (state->save_regions) {
		add_region(line + 1, success, state->previous_region);
	}
}
void ShaderPreprocessor::process_ifndef(Tokenizer *p_tokenizer) {