### 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)

String el = p_path.get_extension().to_lower();
	if (el == "gdshader") {
		return "Shader";
	}
	return "";
}
Error ResourceFormatSaverShader::save(const Ref<Resource> &p_resource, const String &p_path, uint32_t p_flags) {
	Ref<Shader> shader = p_resource;
	ERR_FAIL_COND_V(shader.is_null(), ERR_INVALID_PARAMETER);
	String source = shader->get_code();
	Error err;
	Ref<FileAccess> file = FileAccess::open(p_path, FileAccess::WRITE, &err);
	ERR_FAIL_COND_V_MSG(err, err, "Cannot save shader '" + p_path + "'.");
	file->store_string(source);
	if (file->get_error() != OK && file->get_error() != ERR_FILE_EOF) {
		return ERR_CANT_CREATE;
	}
	return OK;
}
void ResourceFormatSaverShader::get_recognized_extensions(const Ref<Resource> &p_resource, List<String> *p_extensions) const {
	if (const Shader *shader = Object::cast_to<Shader>(*p_resource)) {
		if (shader->is_text_shader()) {
			p_extensions->push_back("gdshader");
		}
	}
}
bool ResourceFormatSaverShader::recognize(const Ref<Resource> &p_resource) const {
	return p_resource->get_class_name() == "Shader"; 
}