CI: remove Python cache
CI: remove Python cache

Since we are still testing obsolete/unsupported Python versions, this is a workaround for the Windows Python 3.5 error.

It should be reverted later when support for Python 3.5 is dropped.

StevenBlack/hosts,StevenBlack/hosts,gfyoung/hosts,gfyoung/hosts,borisschapira/hosts