[Rust] Fix clippy lint

[GreenPenguino]

Creating a Rust codec and linting the generated code using clippy gives the following warning:

warning: variables can be used directly in the `format!` string
   --> src/lib.rs:123:9
    |
123 |         write!(f, "{:?}", self)
    |         ^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
    = note: `#[warn(clippy::uninlined_format_args)]` on by default
help: change this to
    |
123 -         write!(f, "{:?}", self)
123 +         write!(f, "{self:?}")
    |

warning: `io_aeron_archive_codecs` (lib) generated 1 warning

This PR fixes that.