manifest: add missing entry for extmsg_event_step_regression.t

Fixes: 18420b5f (extmsg: fix Message-ID search for non-xap_helper users, 2025-10-21)

diff --git a/MANIFEST b/MANIFEST
index 17be0c53c6a116bf13fbcbaa71186199fb8afa32..46056ae4f2a52b5efbb7c93ba27bf2bbacd106ed 100644 (file)
--- a/MANIFEST
+++ b/MANIFEST
@@ -477,6 +477,7 @@ t/eml_content_disposition.t
 t/eml_content_type.t
 t/epoll.t
 t/extindex-psgi.t
+t/extmsg_event_step_regression.t
 t/extsearch.t
 t/fail-bin/spamc
 t/fake_inotify.t