Update to using pyarrow 14.0.0

[amrit110]

Motivation: describe the problem to be solved
Nannyml uses pyarrow (>=12.0.0,<13.0.0).

Describe the solution you'd like
Update to using latest version of pyarrow (v0.15.0) which has several improvements or atleast v0.14.0

[amrit110]

Hi! @nnansters would this be a straightforward update? Can i attempt at submitting a PR?

[nnansters]

Hey @amrit110 , definitely. Just be aware that we need to maintain Python 3.7 support, which might require conditional imports. Like we did with numpy.

Thanks for looking into this, haven't had the time for it yet. Also our dependencies are in bad shape right now 😅

[amrit110]

Thanks @nnansters! Yeah, understand the pains of dependency management :). Have submitted a PR.