This reverts commits 86fc053269 and cebf6aa8fd.
The intention is to delay the huge rebuild, as we do have binaries
for the non-reproducible builds already.
Some tests required pytz, some tests are just broken two times a year
on days when EST is moving from and to daylight saving time.
Now with that out of the way, some general goodness towards the package.
checkInputs used to be added to nativeBuildInputs. Now we have
nativeCheckInputs to do that instead. Doing this treewide change allows
to keep hashes identical to before the introduction of
nativeCheckInputs.
