Update GUPAX to current versions of packaged software
Update Gupax to include the latest underlying packages:

[P2Pool v3.7](https://github.com/SChernykh/p2pool/releases/tag/v3.7)

[Monero v0.18.3.1](https://github.com/monero-project/monero/releases/tag/v0.18.3.1)

Latest version of XMRig.