Upgrade pandas in BQ samples lagging in python 3.10

[leahecole]

Description

Fixes#7037

Note: It's a good idea to open an issue first for discussion.

Checklist

• I have followed Sample Guidelines from AUTHORING_GUIDE.MD
• README is updated to include all relevant information
• Tests pass: nox -s py-3.6 (see Test Environment Setup)
• Lint pass: nox -s lint (see Test Environment Setup)
• These samples need a new API enabled in testing projects to pass (let us know which ones)
• These samples need a new/updated env vars in testing projects set to pass (let us know which ones)
• Please merge this PR for me once it is approved.
• This sample adds a new sample directory, and I updated the CODEOWNERS file with the codeowners for this sample

[dandhlee]

Oops, sorry accidentally merged the wrong PR D:

@tswast or @loferris could you take a quick look to see if it's okay? Wanted your feedback before we merged it.

[tswast]

LGTM, thanks!