[Python] Remove direct usage of pandas' Block subclasses

[asfimport]

The CategoricalBlock was removed in pandas (pandas-dev/pandas#40527), which breaks the nightly tests.

I will argue in pandas to add it back on the short term (pandas-dev/pandas#40226 (comment)), but we should still remove the direct use of those Block subclasses in pyarrow.

Reporter: Joris Van den Bossche / @jorisvandenbossche
Assignee: Joris Van den Bossche / @jorisvandenbossche

PRs and other links:

• GitHub Pull Request #10017

_{Note: This issue was originally created as ARROW-12057. Please see the migration documentation for further details.}

[asfimport]

Krisztian Szucs / @kszucs:
@jorisvandenbossche is this something we need to ship with 4.0?

[asfimport]

Joris Van den Bossche / @jorisvandenbossche:
Issue resolved by pull request 10017
#10017