BUG: IntervalIndex.get_indexer incorrectly matching ints to datetimes

[jbrockmendel]

• closes API: IntervalIndex.get_indexer not strict about passed target values dtype #47772 (Replace xxxx with the GitHub issue number)
• Tests added and passed if fixing a bug or adding a new feature
• All code checks passed.
• Added type annotations to new arguments/methods/functions.
• Added an entry in the latest doc/source/whatsnew/vX.X.X.rst file if fixing a bug or adding a new feature.

[mroeschke]

Thanks @jbrockmendel

[rhshadrach]

This patch may have induced a performance regression. If it was a necessary behavior change, this may have been expected and everything is okay.

Please check the links below. If any ASVs are parameterized, the combinations of parameters that a regression has been detected for appear as subbullets.

• reshape.Cut.time_qcut_timedelta
  • bins=4
• reshape.Cut.time_qcut_float
  • bins=10
  • bins=4

Subsequent benchmarks may have skipped some commits. The link below lists the commits that are between the two benchmark runs where the regression was identified.

a98be06...28f274c