Pip was using the same cache for multiple versions, so for Python version specific packages they were almost always missing the cache.
This PR keeps a cache per Python version and separate ones for the upstream tests as well. The cache restore keys allow sharing between versions or between the upstream and regular tests.
Pip was using the same cache for multiple versions, so for Python version specific packages they were almost always missing the cache.
This PR keeps a cache per Python version and separate ones for the upstream tests as well. The cache restore keys allow sharing between versions or between the upstream and regular tests.