fix: bump tokio to address RUSTSEC-2026-0386 (#4642)

Upgrade the locked Tokio version from 1.53.1 to 1.53.3 to fix
[RUSTSEC-2026-0386](https://rustsec.org/advisories/RUSTSEC-2026-0386)
and restore the Rust workflow's `deny` job. The diff changes only
Tokio's version and checksum.

Validation:
- `cargo deny check advisories` — passed.
- `cargo deny check advisories bans licenses sources` — passed with the
repository's `deny.toml`.
- `cargo check --quiet -p lancedb` — passed (dead-code warnings).
- PR `deny` job —
[passed](https://github.com/lancedb/lancedb/actions/runs/40000920646/job/120576455117).

Cargo.lock

@@ -10446,9 +10446,9 @@ dependencies = [
 
 [[package]]
 name = "tokio"
-version = "1.53.1"
+version = "1.53.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "202caea871b69668250d242070849eb495be178ed697a3e98aebce5bc81a0bed"
+checksum = "ce3335fa71841cda333a58d7615b03901380ecf09d59b3296d21f8bbac0dde4e"
 dependencies = [
  "bytes",
  "libc",