* chore: add script to compute code samples coverage

* include Index, Session and ml.ensemble

Thank you for opening a Pull Request! Before submitting your PR, there are a few things you can do to make sure it goes smoothly:
- [ ] Make sure to open an issue as a [bug/issue](https://togithub.com/googleapis/python-bigquery-dataframes/issues/new/choose) before writing your code!  That way we can discuss the change, evaluate designs, and agree on the general idea
- [ ] Ensure the tests and linter pass
- [ ] Code coverage does not decrease (if any source code was changed)
- [ ] Appropriate docs were updated (if necessary)

Fixes #<issue_number_goes_here> 🦕

* test: include model.register test for BQML CMEK

* propagate _start_query_create_model renaming in unit test

* add a side assert in to_gbq tes

* feat: support CMEK for `remote_function` cloud functions

* add retry in test

* bump up min version of google-python-functions for CMEK compliance

Fixing internal bugs:
line: b/322177942
scatter: b/322178336
area: b/322178394

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>