unknown type declaration for catch argument doesn't work in js

[elibarzilay]

From #36775, unknown doesn't work in JS with a jsdoc comment:

try {
	// something
} catch (/** @type {unknown} */ err) {
	// `err` is still typed as `any`:
	err; // $ExpectType unknown
}

[bajtos]

Because of this bug, it's not possible to use @typescript-eslint/no-implicit-any-catch to lint JavaScript code using JSDoc comments for type annotations (see https://devblogs.microsoft.com/typescript/how-to-upgrade-to-typescript-without-anybody-noticing-part-2/).

[DanielRosenwasser]

Thanks @a-tarasyuk!