chore: merge upstream gas escalator and run test (#14)

Fixes some issues @tkporter brought up in
hyperlane-xyz/hyperlane-monorepo#3852 (review):
1. Holding mutex lock across gas escalations (fixed upstream, I just
merged the changes)
2. Silently ignoring nonce related errors: added a `warn` log. These
error are only expected to occur if the original tx landed onchain
though
3. I ran the unit test that comes with this middleware, and similar to
what Trevor pointed out, sending a tx returns a `PendingTransaction`
whose tx hash will not reflect the hash of the tx that lands onchain.
However I manually checked by polling anvil and emitting logs that the
gas is escalated and the final tx is finalized

ethers-middleware/Cargo.toml

@@ -27,6 +27,7 @@ serde = { version = "1.0.124", default-features = false, features = ["derive"] }
 thiserror = { version = "1.0", default-features = false }
 futures-util = { version = "^0.3" }
 futures-locks = { version = "0.7", default-features = false }
+futures-channel.workspace = "0.3.28"
 tracing = { version = "0.1.37", default-features = false }
 tracing-futures = { version = "0.2.5", default-features = false }
 

ethers-middleware/src/gas_escalator/linear.rs

@@ -33,7 +33,6 @@ impl LinearGasPrice {
 impl GasEscalator for LinearGasPrice {
     fn get_gas_price(&self, initial_price: U256, time_elapsed: u64) -> U256 {
         let mut result = initial_price + self.increase_by * (time_elapsed / self.every_secs);
-        dbg!(time_elapsed, self.every_secs);
         if let Some(max_price) = self.max_price {
             result = std::cmp::min(result, max_price);
         }