function createEslintrcErrorSchema(key) {
	return {
		merge: "replace",
		validate() {
			throw new IncompatibleKeyError(key);
		},
	};
}
Creates a schema that always throws an error. Useful for warning
about eslintrc-style keys.
@param {string} key The eslintrc key to create a schema for.
@returns {ObjectPropertySchema} The schema.