Fix Series construction from Sparse["datetime64[ns]"]

[dsaxton]

• closes BUG: Sparse[datetime64[ns]] TypeError: data type not understood #35762
• tests added / passed
• passes black pandas
• passes git diff upstream/master -u -- "*.py" | flake8 --diff
• whatsnew entry

[jbrockmendel]

LGTM

[jreback]

thanks @dsaxton

[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 1.1.x
$ git pull

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

$ git cherry-pick -m1 d0ca4b347b060bc4a49b2d31a818d5a28d1e665f

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

$ git commit -am 'Backport PR #35838: Fix Series construction from Sparse["datetime64[ns]"]'

4. Push to a named branch :

git push YOURFORK 1.1.x:auto-backport-of-pr-35838-on-1.1.x

5. Create a PR against branch 1.1.x, I would have named this PR:

"Backport PR #35838 on branch 1.1.x"

And apply the correct labels and milestones.

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

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

[dsaxton]

Manual backport PR: #35915