fmow and Pandas 2.0.0 datetime conversion

[somussma]

I'm getting an error when initializing the "fmow" dataset. I got the following error for the conversion of the timestamp to datetime with Pandas:

ValueError: time data "2011-02-07T02:48:56.643Z" doesn't match format "%Y-%m-%dT%H:%M:%S%z", at position 92. You might want to try:
- passing format if your strings have a consistent format;
- passing format='ISO8601' if your strings are all ISO8601 but not necessarily in exactly the same format;
- passing format='mixed', and the format will be inferred for each element individually. You might want to use dayfirst alongside this.

I noticed I was using Pandas 2.0.0 (presumably the most recent version) and when I reverted to Pandas 1.5.3, the issue seemed to go away. I'm guessing the datetime formatting was changed in version 2 and it might be good to update WILDS to still work with the new version. Thanks!