Bump rust-g to 0.8.0

According to tgstation/rust-g#101 (or tgstation/rust-g@76fd17a ), this version of rust-g makes Cellular Noise faster. We leverage the shit out of Cellular Noise in our cave generation across all maps (especially IceBoxStation), so I am very keen on seeing this.

Here are some scuffed results from my local test on this claim, where you seem to see a not-bad 0.2 second reduction with the bumped DLL on my debug server:

Might also be nice to use the other types of noise one day. One day. Also contains some more cargo crates or whatever you wanna call it. Cool.