Add sort option recentclose for issues and pulls (#34525) (#34539)

Backport #34525 by @MarkusAmshove

closes #34171 

Adds a new sort option `recentclose` for issues and pull requests which
will return items in a descending order of when they were closed

Co-authored-by: Markus Amshove <scm@amshove.org>

routers/api/v1/repo/pull.go

@@ -73,7 +73,7 @@ func ListPullRequests(ctx *context.APIContext) {
 	//   in: query
 	//   description: Type of sort
 	//   type: string
-	//   enum: [oldest, recentupdate, leastupdate, mostcomment, leastcomment, priority]
+	//   enum: [oldest, recentupdate, recentclose, leastupdate, mostcomment, leastcomment, priority]
 	// - name: milestone
 	//   in: query
 	//   description: ID of the milestone