rustls-pemfile is failing CI

[cijothomas]

https://github.com/open-telemetry/otel-arrow/actions/runs/19973542702/job/57283950963?pr=1532

error[unmaintained]: rustls-pemfile is unmaintained
┌─ /github/workspace/rust/otap-dataflow/Cargo.lock:447:1
│
447 │ rustls-pemfile 2.2.0 registry+https://github.com/rust-lang/crates.io-index
│ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ unmaintained advisory detected
│
├ ID: RUSTSEC-2025-0134
├ Advisory: https://rustsec.org/advisories/RUSTSEC-2025-0134
├ The rustls-pemfile crate is no longer maintained. The repository has been archived since August
2025, and users are encouraged to depend directly on the underlying PEM parsing code included
in rustls-pki-types since 1.9.0. The latest version of rustls-pemfile is in fact a thin wrapper
around the same code used in rustls-pki-types, so migrating should be straightforward.

  The new API is represented by the [`PemObject`][PemObject] trait, which provides methods for
  reading a single or multiple PEM objects from a file or byte slice.
  
  [PemObject]: https://docs.rs/rustls-pki-types/latest/rustls_pki_types/pem/trait.PemObject.html
├ Announcement: https://github.com/rustls/pemfile/issues/61
├ Solution: No safe upgrade is available!
├ rustls-pemfile v2.2.0
  └── otap-df-otap v0.1.0
      └── otap-df v0.1.0

advisories FAILED

[cijothomas]

@lalitb Do you want to take this?

[albertlockett]

@cijothomas added to deny.toml as a temporary workaround until we implement the solution outlined in the issue description