[Reader] Tag posts list not fetching new pages

[RenanLukas]

Expected behavior

When we scroll the posts list of a tag, we should continue to fetch the next pages.

Actual behavior

When we scroll the posts list of a tag, paging stops working at some point even when there are still posts that match the filter.

Steps to reproduce the behavior

• Install JP and sign-in
• Open "Reader"
• Select a tag
• Start scrolling: it will stop loading new posts at some point, even though there are many more (compare with web)

Another way to test is opening the tag posts list from blogging prompts card:

• Install JP and sign-in
• Open "My Site"
• Tap on "View all responses" in blogging prompts card
• Start scrolling: it will stop loading new posts at some point, even though there are many more (compare with web)

Tested on emulator, Android 14, JPAndroid / WPAndroid 23.7

[RenanLukas]

Fixed by #19881