CI builds fail if cmake version < 2.21.1

The [CMakeLists](https://github.com/googleapis/cpp-bigquery-odbc/blob/main/google/cloud/odbc/CMakeLists.txt) file is unable to find the package `google_cloud_cpp_bigquery_rest`, if the cmake version installed is < 2.21.1. This leads to CI failures on all linux distributions.

Error logs:
```
-- Build files have been written to: /workspace/cmake-out
make[2]: *** No rule to make target 'google/cloud/odbc/google_cloud_cpp_bigquery_rest', needed by
'google/cloud/odbc/CMakeFiles/odbc_client_interface'. Stop.
make[1]: *** [CMakeFiles/Makefile2:1276: google/cloud/odbc/CMakeFiles/odbc_client_interface.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....
```

For more details: refer the [cloudbuild logs](https://pantheon.corp.google.com/cloud-build/builds;region=us-east1/6d09136e-2c67-4131-bcce-4b397d7a5dad?project=bigquery-devtools-drivers)