REGR: fix DataFrame reduction with EA columns and numeric_only=True
Closes #33256

For the block-wise path in `DataFrame._reduce`, we ensure to use the EA reduction for blocks holding EAs, instead of passing the EA to the `op` function (which is typically the `nanops` nan function).

This needs https://github.com/pandas-dev/pandas/pull/33758 to be merged, since that PR fixes the test that is failing here.