chore: add cross-env so jest script runs on windows

[NaridaL]

Fixes #

Proposed changes

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[armano2]

env varibales are not really needed if we update/cleanup dependencies #88

[NaridaL]

ok well it looks like metapak doesn't like my change, but without it I can't run the preversion sript on windows so not sure how to resolve this.

@nfroidure

[NaridaL]

env varibales are not really needed if we update/cleanup dependencies #88

That's a bit more than a cleanup no? Why replace jest?

[armano2]

metapak hasn't been updated in a while, and it's regenerating all files every time when its run, thats also a reason why #81 is failing