enum.EnumMeta renaming

[JelleZijlstra]

#22392 renamed the enum.EnumMeta metaclass to enum.EnumType. This originally went into 3.10 and was reverted (#27010), but remained on 3.11.

The renaming caused some problems for me with introspection code that looks at the name of classes to find their stubs (quora/pyanalyze#537).

I don't see anything wrong with the old name (EnumMeta). Could we return to the EnumMeta name to avoid gratuitously making upgrades harder?

cc @ethanfurman for enum

[ethanfurman]

My apologies for the extra work. I renamed it (and kept the old name as an alias) because I personally found it confusing when working with enums to have, for example, SelectionEnum be of type EnumMeta and not EnumType.

The change is not gratuitous.