test: add an IgnoreOnWeb annotation

[Luna712]

For some things like coroutines, when compiled to JS tests will fail because it is single threaded, and it can't cancel a synchronous operation from a single threaded system. That causes a few tests from #2812 to fail on JS only, rather than splitting the location for the tests per platform, which can make it harder to find, just ignoring the tests would be better. With this we could then just add @IgnoreOnWeb to the tests we don't care about. The actual in webTest would later be:

package com.lagradost.cloudstream3.utils

import kotlin.test.Ignore

actual typealias IgnoreOnWeb = Ignore

and because of @OptionalExpectation, we don't need to add actual to any other source sets. I decided to do this as a different PR rather than in #2812 because it is kinda different scope after all, and I don't want to drift that scope to much.

I also used Ignore.kt as the file name because IgnoreOnWeb.kt would mean for webTest it would be IgnoreOnWeb.web.kt which just seems a bit odd. Additionally this way if we ever need we could also add more in the same file like IgnoreOnJvm or IgnoreOnAndroid.