Explicitly cast "limit" (page size) API parameter to int

Summary:
Do not throw an exception when the limit (page size) Conduit API parameter is a float but explicitly convert to int.
As an admin, I am not interested in having invalid user-committed query data trigger an error in the server logs.

ERROR 8192: Implicit conversion from float to int loses precision at [/var/www/html/phorge/phorge/src/view/control/AphrontCursorPagerView.php:76]

Closes T15810

Test Plan: Call /conduit/method/maniphest.search/ with a float value for the limit field. Check the server logs or DarkConsole.

Reviewers: O1 Blessed Committers, valerio.bozzolan

Reviewed By: O1 Blessed Committers, valerio.bozzolan

Subscribers: speck, tobiaswiese, valerio.bozzolan, Matthew, Cigaryno

Maniphest Tasks: T15810

Differential Revision: https://we.phorge.it/D25614