Closes#221
This contains (in the static linux sdk but the swift version and the sdk
must match) libarchive support and mimalloc! This also (unrelated to the
sdk bump it seems) raises the amount of retries we do when dialing
vminitd. It seems CI on rare occasions recently has timed out on some
tests. We could also explore just lowering the concurrency on the
integration suite.
Everytime we grab a vsock connection we dup the conn and close the
original, otherwise we'd need to carry around the vsock connection type
everywhere as it closes the fd in its destructor. We weren't checking
the return value of dup however, so if it did fail we'd have a useless
filehandle with an fd of -1.