gh-41431: Add `datetime.time.strptime()` and `datetime.date.strptime()` (#120752)

gh-41431: Add `datetime.time.strptime()` and `datetime.date.strptime()` (#120752)

* Python implementation

* C implementation

* Test `date.strptime`

* Test `time.strptime`

* 📜🤖 Added by blurb_it.

* Update whatsnew

* Update documentation

* Add leap year note

* Update 2024-06-19-19-53-42.gh-issue-41431.gnkUc5.rst

* Apply suggestions from code review

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
* Remove parentheses

* Use helper function

* Remove bad return

* Link to github issue

* Fix directive

* Apply suggestions from code review

Co-authored-by: Paul Ganssle <1377457+pganssle@users.noreply.github.com>
* Fix test cases

---------

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
Co-authored-by: Paul Ganssle <1377457+pganssle@users.noreply.github.com>