Bump default maxBufferSize

[clairemcginty]

See discussion here; some repos are still overflowing the buffer size and not receiving scala-steward updates.

[clairemcginty]

cc @mzuehlke would you mind taking a look? :)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.76%. Comparing base (d72680d) to head (4dea918).
⚠️ Report is 11 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3694   +/-   ##
=======================================
  Coverage   89.76%   89.76%           
=======================================
  Files         174      174           
  Lines        5049     5049           
  Branches      493      452   -41     
=======================================
  Hits         4532     4532           
  Misses        517      517           

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[mzuehlke]

Thanks @clairemcginty 👍