This change updates the default behavior of BigQuery DataFrames to be less verbose during execution.

User-facing changes:

• Quiet by Default: The default value for bigframes.options.display.progress_bar is now None (previously "auto"). This means operations triggering BigQuery jobs will execute silently without displaying progress bars or completion messages in the output.
• Opt-in for Verbosity: Users who prefer to see progress feedback can easily re-enable it by setting the option explicitly:

   1     import bigframes.pandas as bpd
   2
   3     # Restore previous behavior
   4     bpd.options.display.progress_bar = "auto"
   5
   6     # Or specify a specific mode
   7     # bpd.options.display.progress_bar = "terminal"
   8     # bpd.options.display.progress_bar = "notebook"

This change aims to provide a cleaner default experience, especially for users running multiple operations in sequence or in non-interactive environments.

Fixes #<481804767> 🦕