[CAI-25] Update sponsor.md

Author: aameen79

content/events/2025-cairo/sponsor.md

@@ -10,7 +10,10 @@ border:1px solid black;
 }
 </style>
 
-<p style="text-align: center;"><h3>Sponsorship Packages</h3></p>
+<p style="text-align: center;"><h3>Sponsorship Packages</h3>
+
+  Deadline to submit your Request for Sponsorship is 31 August 2025.
+</p>
 
 <table style="width: 98%;" border="1">
 <tbody>