Summary:
Increment YBC client and server version to 2.2.0.3-b6

Includes commit:
- [PLAT-18452] https://github.com/yugabyte/ybc/commit/56851407f22f9e5812be0cabbfc80193ea8ca574
- [PLAT-18425] https://github.com/yugabyte/ybc/commit/9b2ce5501c43c9e1298f23e755ec46f205b2f532

Test Plan: dev itests

Reviewers: agunta, dshubin

Reviewed By: agunta

Differential Revision: https://phorge.dev.yugabyte.com/D46473