Update to rand 0.9

[Jengamon]

Bump code to use rand 0.9 by translating API calls:

• gen* -> random*
• from_entropy -> from_os_rng

[Aeledfyr]

We may want to make rand optional, or directly expose RNG seeding through the API before upgrading to rand 0.9; that bumps getrandom to 0.3, which is more difficult to get working on WASM. (getrandom is an annoyingly painful dependency to manage.)

It should be straightforward to split load_random (and load_math) into variants that initialize from a seed and variants that use OS apis, and put the ones that require getrandom behind a feature flag. I may go and fix that at some point when I have time, but until then I'm personally stuck on rand 0.8.

[Jengamon]

Would making the rng an argument be a path we'd want to go down?

Different applications might want different random number properties, and then we could turn off all default features, and have a feature that provides the old load_math interface with os-seeded rng.

[Jengamon]

We may want to make rand optional, or directly expose RNG seeding through the API before upgrading to rand 0.9; that bumps getrandom to 0.3, which is more difficult to get working on WASM. (getrandom is an annoyingly painful dependency to manage.)

It should be straightforward to split load_random (and load_math) into variants that initialize from a seed and variants that use OS apis, and put the ones that require getrandom behind a feature flag. I may go and fix that at some point when I have time, but until then I'm personally stuck on rand 0.8.

I haven't been having too many problems after sticking

[target.wasm32-unknown-unknown]
rustflags = '--cfg getrandom_backend="wasm_js"'

into .cargo/config.toml relative to the crate I want to compile for wasm (along with the feature addition in Cargo.toml)

EDIT: they tell you this on the crate docs page ignore me