chore(docs): use read_rows_stream in filter samples

[daniel-sanche]

replace read_rows with read_rows_stream, as it is more efficient

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Fixes #<issue_number_goes_here> 🦕

[igorbernstein2]

what makes this more efficient?

[daniel-sanche]

what makes this more efficient?

context: b/347322404

read_rows buffers the entire output before returning the resulting list, read_rows_stream streams gives a generator for acting on the results as they arrive

[daniel-sanche]

After discussing this offline, I think we will leave as-is