cargo automated fixes

[fenris02]

There are some cargo automation commands to help:

1. reformat Cargo.toml,
2. update crates and regenerate fresh lock file,
3. correct a minor code warning,
4. set the minimum supported rust version,
5. tune the package,
6. remove unused dependencies,
7. update the package version

cargo tomlfmt ; cargo fmt ; 
rm Cargo.lock ; cargo update ; cargo update --locked ; cargo upgrade --verbose ; 
cargo clippy --fix --bin "quicssh-rs" ;
cargo wizard apply fast-compile dev ; cargo wizard apply fast-runtime release ;
cargo udeps --all-targets ;
cargo msrv list ;
cargo bump -g -p dev

The change set (patch) is rather large because it resorts Cargo.lock, but the actual code changes are very minor.

Cargo.toml | 48 ++++++++++++++++++++++++++++++++++--------------
rust-toolchain.toml | 3 +++
src/client.rs | 22 ++++++++++------------
src/server.rs | 4 ++--
4 files changed, 49 insertions(+), 28 deletions(-)

quicssh-rs-2024-04-20.patch