otel: Update crates

Run 'cargo update' to get the latest version of the required crates in
preparation for the 1.34.0 release.

The rustls update fixes a panic in `rustls::server::Acceptor::accept()`,
but Unit does not use this code path and was not affected.

Link: <https://rustsec.org/advisories/RUSTSEC-2024-0399.html>
Link: <https://github.com/nginx/unit/security/dependabot/11>
Closes: <#1503>
Signed-off-by: Andrew Clayton <[email protected]>