DEPS: Partial Matplotlib 3.7 support
xref https://github.com/pandas-dev/pandas/issues/51394

These pass locally with 3.7, the remaining issue will be address with https://github.com/matplotlib/matplotlib/issues/25219
You may have to do version checks for `legend_handles` vs `legendHandles` if you don't want to pin to mpl3.7, the snake case version is new, but is preferred going forward, the camel case version was not actually meant to be fully public (it wasn't documented, but it also didn't have an `_`, so it got used) thx @mroeschke 

I think we should backport, feel free to close the pr if you think differently Agreed would be worth backporting