* bench-api: configure WASI modules based on passed flags
When benchmarking in Sightglass, @brianjjones has found it necessary to
enable the wasi-nn module. The current way to do so is to alter the
engine build script to pass `--features wasi-nn` so that this crate can
run code relying on these imports. This change allows the user to
instead pass the WASI modules using the engine flags added in #4096.
This could look something like the following in Sightglass:
```
sightglass-cli benchmark ... --engine-flags '--wasi-modules experimental-wasi-nn'
```
* fix: disable wasi-crypto as a default feature
5a288c2c40