#505 #473 Upgrade kaspa-alloc's mimalloc dependency

[saefstroem]

What is this
This PR closes #505, #473.

How
By upgrading the mimalloc dependency to version 0.1.43 which uses version 2.1.7 version of mimalloc.

Tests performed
Problems specified in #473 were resolved through a manual test by @blackmennewstyle.

Why do we need it

kaspa-alloc uses an outdated dependency of mimalloc rust crate 0.1.39 which uses the 2.1.2 version of the mimalloc impl by Microsoft.

In this outdated dependency there is a problem of compilation on some systems: microsoft/mimalloc#883

This is fixed in a later version of mimalloc hence the reason for why we need to upgrade the dependency in the kaspa-alloc crate.

[saefstroem]

@michaelsutton @aspect