test: set nonce explicitly

[mattsse]

Motivation

gets rid of a flaky test as seen here https://github.com/gakonst/ethers-rs/runs/6740032643?check_suite_focus=true
by explicitly setting the nonce

there's a possible race condition rn on anvil if multiple tx without nonce are sent via eth_sendTransaction because the next nonce is determined by onchain +num(pool)
however if multiple tx are sent at the same time they might get the same nonce if the nextNonce for an additional tx is determined before the previous was added to the pool.

https://github.com/foundry-rs/foundry/blob/25241a63db896c88b1717c5522ac284724003eb8/anvil/src/eth/api.rs#L547

https://github.com/foundry-rs/foundry/blob/25241a63db896c88b1717c5522ac284724003eb8/anvil/src/eth/api.rs#L569

this could be prevented via an import lock or some additional check against the Already Imported error but not sure if that's worth it @gakonst ?

the former would have some performance impact because we need to lock for the entire sendTransaction function, for the latter we can try to implement an additional attempt: if tx.nonce was None and we received an Already Imported error try again with new nonce until not Already Imported error.

Solution

• also ran cargo clippy fix

failing watch_events test fixed in anvil: foundry-rs/foundry#1861

PR Checklist

• Added Tests
• Added Documentation
• Updated the changelog