Fix MSRV build err from `regex-automata` via `cargo-ndk`.

[cpu]

The scheduled CI job is hitting a failure w/ the MSRV tasks: https://github.com/rustls/rustls-platform-verifier/actions/runs/6486318645

  Downloaded libc v0.2.149
error: failed to compile `cargo-ndk v2.12.7`, intermediate artifacts can be found at `/tmp/cargo-installX3AYQ8`

Caused by:
  package `regex-automata v0.4.1` cannot be built because it requires rustc 1.65 or newer, while the currently active rustc version is 1.64.0
Error: Process completed with exit code 101.

Putting this in the tracker so it doesn't get lost in the shuffle.