Use MD5 usedforsecurity=False on Python 3.9 and higher

[simonw]

Refs:

• Use of md5 hash causes FIPS error, requires usedforsecurity=False #2270

[simonw]

I manually tested this fix in a FIPS Ubuntu Docker image using the steps outlined here and the tests passed too:

• Use of md5 hash causes FIPS error, requires usedforsecurity=False #2270 (comment)

[simonw]

Crucially the tests passed against Python 3.8, which demonstrates that this branch works:

datasette/datasette/utils/__init__.py

Lines 1406 to 1411 in 2273a4b

	def md5_not_usedforsecurity(s):
	try:
	return hashlib.md5(s.encode("utf8"), usedforsecurity=False).hexdigest()
	except TypeError:
	# For Python 3.8 which does not support usedforsecurity=False
	return hashlib.md5(s.encode("utf8")).hexdigest()