The latest version of eslint-config-wikimedia requires spaces inside template literal expressions. In Vector, ensure that spaces are added inside the expressions of template literal expressions. This adjustment aligns with the updated eslint-config-wikimedia rules.
document.documentElement.classList.remove(`${featureName}-clientpref-${possibleValue}`);
to
document.documentElement.classList.remove(`${ featureName }-clientpref-${ possibleValue }`);