update changelog

Author: annie-mac

sdk/cosmos/azure-cosmos/CHANGELOG.md

@@ -13,6 +13,7 @@
 * Changed to use `PartitionKeyRangeCache` to get partition key range during startup and split handling. - [46700](https://github.com/Azure/azure-sdk-for-java/pull/46700)
 * Changed to use lower casing http header names for gateway response. - [46736](https://github.com/Azure/azure-sdk-for-java/pull/46736)
 * Improved resilience around several completion events for an ssl handshake. - [PR 46734](https://github.com/Azure/azure-sdk-for-java/pull/46734)
+* Changed to use incremental change feed to populate partition key ranges. - [46810](https://github.com/Azure/azure-sdk-for-java/pull/46810)
 
 ### 4.74.0 (2025-09-05)