### Godot version

v4.0.beta13.official [caacade56]

### System information

Linux Ubuntu 20.04 with Unity desktop

### Issue description

When calling an undefined function in the shader editor with argument(s), such as `undefined_function(1)`, the error reads:

> Too many arguments for "undefined_function()" call. Expected at most 0 but received 1.

instead of the expected:

> No matching function found for: 'undefined_function'.

This is possibly a regression introduced in https://github.com/godotengine/godot/issues/18225, since the latter was focused on the arguments part.

To avoid such regression in the future, consider adding a unit test with this case (and, in fact, unit tests for the other signature errors too if there are not already).

### Steps to reproduce

1. Create a shader resource and open the shader editor
2. Enter `undefined_function(1);` in the fragment() definition

### Minimal reproduction project

N/A
}
				while (builtin_func_defs[idx].name) {
					if (low_end && builtin_func_defs[idx].high_end) {
						idx++;
						continue;
					}
					matches.insert(String(builtin_func_defs[idx].name), ScriptLanguage::CODE_COMPLETION_KIND_FUNCTION);
					idx++;
				}
			} else { 
				int idx = 0;
				bool low_end = RenderingServer::get_singleton()->is_low_end();
				while (builtin_func_defs[idx].name) {
					if (low_end && builtin_func_defs[idx].high_end) {
						idx++;
						continue;
					}
					if (builtin_func_defs[idx].tag == completion_class) {
						matches.insert(String(builtin_func_defs[idx].name), ScriptLanguage::CODE_COMPLETION_KIND_FUNCTION);
					}
					idx++;
				}
			}
			for (const KeyValue<String, ScriptLanguage::CodeCompletionKind> &E : matches) {
				ScriptLanguage::CodeCompletionOption option(E.key, E.value);
				if (E.value == ScriptLanguage::CODE_COMPLETION_KIND_FUNCTION) {
					option.insert_text += "(";
				}
				r_options->push_back(option);
			}