Caching for Graal

[masklinn]

I'm not sure how the actions/setup-python caching is supposed to work, but every graal action indicates that it's "not found in the local cache", leading to a 30~35s overhead over cpython and pypy builds every time, contributing to the cost of graal jobs quite significantly (which adds onto graal's own issues).

[gowridurgad]

Hi @masklinn,
Thank you for the feature request. We'll investigate it and come back to you with the details!