Switch to the lark wheel

[rrueth]

It looks like the lark-parser package switched to lark in 2021: https://github.com/lark-parser/lark/releases/tag/1.0.0

Would it be possible to switch cel-python to use lark as a dependency instead of lark-parser? I have a project that is already using lark in which I'd like to use cel-python. But, I can't install both dependencies because they import as lark.