DEV: Add post_id parameter to reset_bump_date route (#25372)

This would allow a theme component (or an API call) to reset the bump
date of a topic to a given post's created_at date.

I picked `post_id` as the parameter here because it provides a bit of
extra protection against accidentally resetting the bump date to a date
that doesn't make sense.

app/controllers/topics_controller.rb

@@ -1151,12 +1151,14 @@ class TopicsController < ApplicationController
 
   def reset_bump_date
     params.require(:id)
+    params.permit(:post_id)
+
     guardian.ensure_can_update_bumped_at!
 
     topic = Topic.find_by(id: params[:id])
     raise Discourse::NotFound.new unless topic
 
-    topic.reset_bumped_at
+    topic.reset_bumped_at(params[:post_id])
     render body: nil
   end