### Godot version

Godot 4.0.3

### System information

Windows 10 64 bits NVIDIA GeForce GTX 1060

### Issue description

Ctrl+K is a shortcut normally used to comment out the current line. It works in the shader editor, but for some reason, it doesn't if your shader has the `.gdshaderinc` extension (aka it's a shader include). Shader Includes are the same language, we should be able to use that feature.

### Steps to reproduce

Create a `.gdshaderinc` file. Write some code in it. Observe you can't use Ctrl+K to comment out lines.

### Minimal reproduction project

[CommentLinesShaderInc.zip](https://github.com/godotengine/godot/files/11739881/CommentLinesShaderInc.zip)

set_edited_shader_include(p_shader_inc, p_shader_inc->get_code());
}
void ShaderTextEditor::_shader_changed() {
	
	if (block_shader_changed) {
		return;
	}
	dependencies_version++;
	_validate_script();
}
void ShaderTextEditor::set_edited_shader_include(const Ref<ShaderInclude> &p_shader_inc, const String &p_code) {
	if (shader_inc == p_shader_inc) {
		return;
	}
	if (shader_inc.is_valid()) {
		shader_inc->disconnect(SNAME("changed"), callable_mp(this, &ShaderTextEditor::_shader_changed));
	}
	shader_inc = p_shader_inc;
	shader = Ref<Shader>();
	set_edited_code(p_code);
	if (shader_inc.is_valid()) {
		shader_inc->connect(SNAME("changed"), callable_mp(this, &ShaderTextEditor::_shader_changed));
	}
}
void ShaderTextEditor::set_edited_code(const String &p_code) {