bug: 3.7 may not be supported

[cofin]

https://github.com/cofin/goe/blob/f97c9b65ad43cc160dcb2121be8bbbd9313a3893/pyproject.toml#L25

PyArrow currently specifies Python 3.8 as the lowest supported version. Depending on which version is installed, we may not actually have 3.7 support.

[nj1973]

I thought the way it worked was that, if we install goe on Python 3.7, pip would pull down a version of PyArrow that also supported 3.7? PyArrow v11 for example. Therefore we can support Python 3.7 as long as pip can find a valid combination of all dependencies.