Clean up intermediate files to reduce disk usage

[henrymercer]

This PR cleans up some intermediate files that are created during the install, such as archives and the original path of the tools once we've cached them into the toolcache. This increases the amount of disk available to subsequent steps by about 2 GB, based on some brief experiments on Linux.

To handle cases like Windows sometimes holding onto locks, we run rm with three retries, and continue if cleanup fails.