Update columnar migration version on prepare_release

[hanefi]

This PR aims to contain all the changes to automate what we did in https://github.com/citusdata/citus/pull/6898 to bump columnar versions in all the necessary places when we prepare a new release.

TODO:

• [x] update citus_columnar.control
• [x] create new upgrade and downgrade files for the new columnar migration version
• [x] Either add the logic to update diff changes here, or open a PR on citus to make sure the test outputs do not change when we bump columnar version
• [ ] consider adding tests to cover the columnar version bumps