Support pandas Float64Dtype in boxenplot

[afrendeiro]

Pandas 1.2.0 added a Float64DType type extension. Seaborn boxenplot fails with that input:

data = pd.DataFrame(
   {"cont": np.random.random(20), "cat": np.random.choice(["a", "b"], 20)}
).convert_dtypes()

sns.boxplot(data=data, x='cat', y='cont')  #  okay
sns.boxenplot(data=data, x='cat', y='cont')  # error

At the same time Barplot and Boxplot don't fail. This is because boxenplot is at some point converting the input into a numpy array which makes the array dtype 'object'. That dtype fails when is input to np.isfinite here.

[mwaskom]

This is something that should magically start to work once the work in #2429 is complete.

[afrendeiro]

Cool, sounds good! Feel free to close the PR or just recycle the test case.

[mwaskom]

Closed by #2435