Update PostgreSQL lease start date

Author: welovej

.github/arm-leases/postgresql/Microsoft.DBforPostgreSQL/PostgreSQL/lease.yaml

@@ -1,5 +1,5 @@
 lease:
   resource-provider: Microsoft.DBforPostgreSQL
-  startdate: "2026-06-05"
+  startdate: "2026-05-22"
   duration: P180D
   reviewer: "@vikeshi26"