Extension of #22959.

PR Summary

We are still seeing intermittent failures on OSX with the memory leak check on tkagg.

This is taking the gentler approach and increasing the limits again, however there may may be a case for skipping these tests until we understand:

1. the remaining source of the leak in tk (and if this is even a real leak vs legitimately still held objects)
2. we understand the source of the variation

PR Checklis

Tests and Styling

• Has pytest style unit tests (and pytest passes).
• Is Flake 8 compliant (install flake8-docstrings and run flake8 --docstring-convention=all).