BUG: Use newer than 3.7 python for binder

[bsipocz]

Launching the tutorials in binder, it launches with python 3.7 and therefore numpy 1.21.

We should make sure that we in fact provide a more up-to-date version when demoing for tutorial users (and that we in fact CI the versions that are deployed with e.g. binder)

[bsipocz]

NASA-NAVO/navo-workshop#103 does the trick. This is not something we can test or see the effect of in CI, so given the thumbs up I'll just merge the PR as is.