chore(operator): Add changelog entry

Author: Techassi

crates/stackable-operator/CHANGELOG.md

@@ -16,6 +16,7 @@ All notable changes to this project will be documented in this file.
 
 ### Changed
 
+- Update the end-of-support warning message ([#1103])
 - BREAKING: `ProductOperatorRun` was renamed to `RunArguments` ([#1096]).
 - BREAKING: The `disable_crd_maintenance` field was moved from `RunArguments` into `MaintenanceOptions`.
   The CLI interface is unchanged ([#1096]).
@@ -26,6 +27,7 @@ All notable changes to this project will be documented in this file.
 [#1096]: https://github.com/stackabletech/operator-rs/pull/1096
 [#1098]: https://github.com/stackabletech/operator-rs/pull/1098
 [#1101]: https://github.com/stackabletech/operator-rs/pull/1101
+[#1103]: https://github.com/stackabletech/operator-rs/pull/1103
 
 ## [0.98.0] - 2025-09-22