### 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)

switch (pp_state.completion_type) {
			case COMPLETION_TYPE_DIRECTIVE: {
				List<String> options;
				get_keyword_list(&options, true, true);
				for (const String &E : options) {
					ScriptLanguage::CodeCompletionOption option(E, ScriptLanguage::CODE_COMPLETION_KIND_PLAIN_TEXT);
					r_completion_options->push_back(option);
				}
			} break;
			case COMPLETION_TYPE_PRAGMA: {
				List<String> options;
				ShaderPreprocessor::get_pragma_list(&options);
				for (const String &E : options) {
					ScriptLanguage::CodeCompletionOption option(E, ScriptLanguage::CODE_COMPLETION_KIND_PLAIN_TEXT);
					r_completion_options->push_back(option);
				}
			} break;
			case COMPLETION_TYPE_CONDITION: {
				ScriptLanguage::CodeCompletionOption option("defined", ScriptLanguage::CODE_COMPLETION_KIND_PLAIN_TEXT);
				r_completion_options->push_back(option);
			} break;
			case COMPLETION_TYPE_INCLUDE_PATH: {
				if (p_include_completion_func && r_completion_options) {
					p_include_completion_func(r_completion_options);
				}
			} break;
			default: {
			}
		}
	}