### 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)

TextEdit::LineWrappingMode wrap = shader_editor->get_text_editor()->get_line_wrapping_mode();
			shader_editor->get_text_editor()->set_line_wrapping_mode(wrap == TextEdit::LINE_WRAPPING_BOUNDARY ? TextEdit::LINE_WRAPPING_NONE : TextEdit::LINE_WRAPPING_BOUNDARY);
		} break;
		case EDIT_TOGGLE_COMMENT: {
			if (shader.is_null()) {
				return;
			}
			shader_editor->toggle_inline_comment("//");
		} break;
		case EDIT_COMPLETE: {
			shader_editor->get_text_editor()->request_code_completion();
		} break;
		case SEARCH_FIND: {
			shader_editor->get_find_replace_bar()->popup_search();
		} break;
		case SEARCH_FIND_NEXT: {
			shader_editor->get_find_replace_bar()->search_next();
		} break;
		case SEARCH_FIND_PREV: {
			shader_editor->get_find_replace_bar()->search_prev();
		} break;
		case SEARCH_REPLACE: {
			shader_editor->get_find_replace_bar()->popup_replace();
		} break;
		case SEARCH_GOTO_LINE: {
			goto_line_dialog->popup_find_line(shader_editor->get_text_editor());
		} break;
		case BOOKMARK_TOGGLE: {
			shader_editor->toggle_bookmark();
		} break;