Remove deprecated toRustTarget

[jneem]

This fixes a deprecation warning and doesn't appear to break anything :crossed_fingers:

Re-running the nix build after this change didn't actually build anything new, so I think the derivations are identical.

[github-actions[bot]]

Bencher Report

Branch	2063/merge
Testbed	ubuntu-latest

⚠️ WARNING: The following Measure does not have a Threshold. Without a Threshold, no Alerts will ever be generated!

• Latency

Click here to create a new Threshold
For more information, see the Threshold documentation.
To only post results if a Threshold exists, set the --ci-only-thresholds CLI flag.

Click to view all benchmark results

Benchmark	Latency	nanoseconds (ns)
fibonacci 10	📈 view plot ⚠️ NO THRESHOLD	496,730.00
pidigits 100	📈 view plot ⚠️ NO THRESHOLD	3,193,100.00
product 30	📈 view plot ⚠️ NO THRESHOLD	833,400.00
scalar 10	📈 view plot ⚠️ NO THRESHOLD	1,525,000.00
sum 30	📈 view plot ⚠️ NO THRESHOLD	825,510.00

🐰 View full continuous benchmarking report in Bencher

[jneem]

It does indeed take a while to build. I will finish checking it tomorrow, and merge if everything is ok.

[jneem]

I mean, I was checking locally that the static binary builds but it was taking forever.