feat: Update to rand_core v0.9.0

[GeekMasher]

Updated the password-hash crate and fixed the issues with the changes in the rand_core API.

Let me know if you need / want any other changes done before merging.

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By the way, awesome set of crates in this repository!

[GeekMasher]

There are a few more things that apparently have been deprecated in rand_core such as Error which is no longer present in 0.9.0.

After updating crypto-common crate to 0.9.0 it seems that a few of the APIs return rand_core::Error like these:

• https://github.com/RustCrypto/traits/blob/master/crypto-common/src/lib.rs#L199
• https://github.com/RustCrypto/traits/blob/master/crypto-common/src/lib.rs#L262
• https://github.com/RustCrypto/traits/blob/master/crypto-common/src/lib.rs#L282
• https://github.com/RustCrypto/traits/blob/master/crypto-common/src/lib.rs#L324

How do you want to deal with these cases?

[tarcieri]

@GeekMasher since this PR for password-hash is basically done I'd suggest we leave crypto-common out for now and handle it in a separate PR

[newpavlov]

I would prefer to migrate all trait crates in one PR. We not only need to bump rand_core version but also tweak APIs a bit as discussed in the issue. I recently started drafting it locally, but haven't finished it yet.

[GeekMasher]

I've commited the changes @tarcieri suggested. I'm happy with either suggestions about changing crypto-common. I didn't think it would make breaking / API changes but it seems it will so wanted recommendations before writing any code