chore: upgrade deps

[tomverelst]

Summary

Incremental dependency upgrades, one commit per direct dependency (each independently bisectable/revertable). Verified with cargo build --all-targets and cargo test (Kafka integration tests via testcontainers) against the current toolchain (Rust 1.94.0).

Landed so far (semver-compatible, Cargo.lock only):

• libc 0.2.176 → 0.2.186
• tokio 1.47.1 → 1.52.3 (drops the io-uring/backtrace chain; pulls mio, socket2)
• tracing 0.1.41 → 0.1.44
• tracing-subscriber 0.3.20 → 0.3.23

Remaining (to follow on this branch): compatible bumps for thiserror, csv, futures, strum, pin-project, regex, clap, comfy-table, anyhow, tempfile, serial_test; a batched transitive-churn commit; and major bumps itertools 0.14 → 0.15 and testcontainers 0.26 → 0.27.

Note: the repo's newer clippy toolchain surfaces ~25 pre-existing -D warnings lints unrelated to these bumps; CI gates on cargo fmt + cargo test (not clippy), so those are left out of scope here.

Test plan

• cargo build --all-targets clean after each commit
• cargo test green after the runtime-sensitive tokio bump (53 tests pass)
• cargo fmt --all -- --check clean
• Full cargo test after the remaining compatible batch and each major bump