Infinite Scroll: Sticky posts are missing from archive pages if they are not on the first page.

Here is the url of the test site where you can see the issue. https://iamtakashi16.wordpress.com/category/uncategorized/

To see the issue, click the "Older Posts" to load second batch of posts. Notice a sticky post "2" is missing. This also happens with "Scroll Infinitely" type.

This is most likely because of [this](https://github.com/Automattic/jetpack/blob/master/modules/infinite-scroll/infinity.php#L996) which makes sense for blog index but for everywhere else, we shouldn't exclude sticky posts.

Reproduce the missing sticky post on the linked test site's category archive by clicking "Older Posts," then inspect modules/infinite-scroll/infinity.php around line 996. Compare the archive behavior with the blog index and the "Scroll Infinitely" type. Done means sticky posts appear in later archive batches without changing the intended blog-index behavior.

Written by the indexing model from the issue text.