TST: Avoid hashing np.timedelta64 without unit

[mroeschke]

Avoids

____________________ TestValueCounts.test_value_counts_nat _____________________
[gw3] linux -- Python 3.13.0 /opt/hostedtoolcache/Python/3.13.0/x64/bin/python

self = <pandas.tests.test_algos.TestValueCounts object at 0x7f7c3f35dd20>

    def test_value_counts_nat(self):
        td = Series([np.timedelta64(10000), NaT], dtype="timedelta64[ns]")
        dt = to_datetime(["NaT", "2014-01-01"])
    
        for ser in [td, dt]:
            vc = algos.value_counts_internal(ser)
            vc_with_na = algos.value_counts_internal(ser, dropna=False)
            assert len(vc) == 1
            assert len(vc_with_na) == 2
    
        exp_dt = Series({Timestamp("2014-01-01 00:00:00"): 1}, name="count")
        result_dt = algos.value_counts_internal(dt)
        tm.assert_series_equal(result_dt, exp_dt)
    
>       exp_td = Series({np.timedelta64(10000): 1}, name="count")
E       ValueError: Can't hash generic timedelta64

pandas/tests/test_algos.py:1257: ValueError

[lumberbot-app]

Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

git checkout 2.3.x
git pull

2. Cherry pick the first parent branch of the this PR on top of the older branch:

git cherry-pick -x -m1 0b6cece3acda1ae6e4f582d8276851b02aeac1ea

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

git commit -am 'Backport PR #60416: TST: Avoid hashing np.timedelta64 without unit'

4. Push to a named branch:

git push YOURFORK 2.3.x:auto-backport-of-pr-60416-on-2.3.x

5. Create a PR against branch 2.3.x, I would have named this PR:

"Backport PR #60416 on branch 2.3.x (TST: Avoid hashing np.timedelta64 without unit)"

And apply the correct labels and milestones.

Congratulations — you did some good work! Hopefully your backport PR will be tested by the continuous integration and merged soon!

Remember to remove the Still Needs Manual Backport label once the PR gets merged.

If these instructions are inaccurate, feel free to suggest an improvement.