DEV: Remove useless ordering when searching within a topic. (PR #14676)

Searching within a topic currently does not make use of PG search and we’re simply doing an ilike against the post raw. Furthermore, Post#post_number is already unique within a topic so the other ordering will never ever be used. This change simply makes the query cleaner to read.

GitHub

@udan11 Can you review this for me? Thank you!

Thank you for the review @pmusaraj :+1: