fixup: Fix #595

[cosmix]

This PR fixes #595, by re-exporting parse().

parse() should be re-exported so that the user can just call pendulum.parse() as documented, given that the module is marked with py.typed.

No tests have been modified or added for this bugfix.

[cosmix]

Note that the failing CI test has to do with the fact that the flake8 module that you're using seems to not like the import aliasing that needs to be used to fix the issue addressed by this PR and that exports the parse symbol in __init__.py.

For reference, I'm using the type checker rules listed on the pyright README here, but, to my understanding these are rules common to more type checkers for Python.