Update data/releases/schedule.yaml

Co-authored-by: Tim Bannister <[email protected]>

Author: Rishit-dagli

data/releases/schedule.yaml

@@ -9,6 +9,9 @@ schedules:
   cherryPickDeadline: 2023-09-08
   targetDate: 2023-09-13
   endOfLifeDate: 2024-10-28
+  previousPatches:
+    - release: 1.28.0
+      targetDate: 2023-08-15
 - release: 1.27
   releaseDate: 2024-04-11
   maintenanceModeStartDate: 2024-04-28