forge-ls-recent-topics: Stop caching for now

We started caching in [1: 844aa6d] without providing a reason, but
assuming it has something to with performance is reasonable.  This
cache has to be invalidated in some cases, but determining when that
is work for another day.  Until then we stop caching.  We might also
be able to speed things up, instead of caching.

In [2: 76596a2] we added one case of cache invalidation.  Visiting
a topic should also invalidate the cache, so that status changes are
displayed in the list.  Instead of doing that, we disable the caching
altogether for now.

1: 2020-12-01 844aa6d
   Cache queries used by topic lists in status buffer

2: 2024-01-12 76596a2
   forge-topic-list-order: Zap cache when set

lisp/forge-topic.el

@@ -434,7 +434,7 @@ an error.  If NOT-THINGATPT is non-nil, then don't use
               rows))))
 
 (defun forge-ls-recent-topics (repo table)
-  (magit--with-repository-local-cache (list 'forge-ls-recent-topics table)
+  (progn ; MAYBE resume caching this
     (let* ((id (oref repo id))
            (limit forge-topic-list-limit)
            (open-limit   (if (consp limit) (car limit) limit))