Replace _has_complex_internals #29227

[Aivengoe]

closes #29227

Hi, it my first issues within hacktoberfest.
I replaced _has_complex_internals with isinstance/
Is it possible to import ABCMultiIndex?

[jbrockmendel]

You're going to need to run isort -rc pandas to fix the linting errors. In the reduction.pyx we don't allow imports from core, so the check will need to be something like index.nlevels > 1

[jreback]

also pls merge master, we just update the codebase with another small usage of this (which needs to be changed)

[jbrockmendel]

pushed rebased and isort fixup

[jreback]

@jbrockmendel this needed or did you already remove?

[jbrockmendel]

still needed

[jreback]

ok @Aivengoe can you merge master.

@jbrockmendel feel free to push here if its faster

[jreback]

thanks @Aivengoe and @jbrockmendel