Fix Zed nginx config stat issue

nginx was checking if the file request_filename existed at each request.

Fixes the following issue:
2026/04/13 21:10:27 [crit] 97679#103893: *336960 stat() "request_filename" failed (13: Permission denied)

This is a follow-up for 79263880.

Reviewed By: yousra

Differential Revision: https://devcentral.nasqueron.org/D4063