### 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)

return shader_editor->get_text_editor()->get_saved_version() != shader_editor->get_text_editor()->get_version();
}
void TextShaderEditor::tag_saved_version() {
	shader_editor->get_text_editor()->tag_saved_version();
}
void TextShaderEditor::apply_shaders() {
	String editor_code = shader_editor->get_text_editor()->get_text();
	if (shader.is_valid()) {
		String shader_code = shader->get_code();
		if (shader_code != editor_code || dependencies_version != shader_editor->get_dependencies_version()) {
			shader_editor->set_block_shader_changed(true);
			shader->set_code(editor_code);
			shader_editor->set_block_shader_changed(false);
			shader->set_edited(true);
		}
	}
	if (shader_inc.is_valid()) {
		String shader_inc_code = shader_inc->get_code();
		if (shader_inc_code != editor_code || dependencies_version != shader_editor->get_dependencies_version()) {
			shader_editor->set_block_shader_changed(true);
			shader_inc->set_code(editor_code);
			shader_editor->set_block_shader_changed(false);
			shader_inc->set_edited(true);
		}
	}
	dependencies_version = shader_editor->get_dependencies_version();
}
void TextShaderEditor::_text_edit_gui_input(const Ref<InputEvent> &ev) {