Upgrade proxy crates to edition 2024 (#10942)

This upgrades the `proxy/` crate as well as the forked libraries in
`libs/proxy/` to edition 2024.

Also reformats the imports of those forked libraries via:

```
cargo +nightly fmt -p proxy -p postgres-protocol2 -p postgres-types2 -p tokio-postgres2 -- -l --config imports_granularity=Module,group_imports=StdExternalCrate,reorder_imports=true
```

It can be read commit-by-commit: the first commit has no formatting
changes, only changes to accomodate the new edition.

Part of #10918

proxy/src/serverless/conn_pool_lib.rs

@@ -10,7 +10,7 @@ use parking_lot::RwLock;
 use postgres_client::ReadyForQueryStatus;
 use rand::Rng;
 use smol_str::ToSmolStr;
-use tracing::{debug, info, Span};
+use tracing::{Span, debug, info};
 
 use super::backend::HttpConnError;
 use super::conn_pool::ClientDataRemote;