BUG: distinguish bool from int in object-dtype hash table

[jbrockmendel]

• closes BUG: factorize with objects differentiate 0/1 from False, True #62888

Summary

• In pyobject_cmp() (khash_python.h), added a type guard that returns not-equal when exactly one of the two objects is a Python bool (PyBool_Check). This correctly distinguishes int(0) from bool(False) and int(1) from bool(True) in the khash equality function used by PyObjectHashTable.
• Fixes factorize, unique, duplicated, isin, value_counts, groupby, and Index.get_loc for object-dtype data containing mixed bool/int values.
• No measurable perf impact: the check is a single PyBool_Check (reads the type pointer) on each side, executed only when types already differ.

Test plan

• New tests in test_algos.py for factorize, unique, isin, value_counts, duplicated
• New tests in test_indexing.py for get_indexer, get_loc, is_unique
• New test in test_groupby.py for groupby with mixed bool/int keys
• Existing test suites pass with no regressions

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