Merge bitcoindevkit/bdk#1646: ci: update audit.yml workflow to use actions-rust-lang...

66cf476014e5869c27d54ebf12e554f3ba925283 ci: update audit.yml workflow to use actions-rust-lang/audit (Steve Myers)

Pull request description:

  ### Description

  Update `audit.yml` workflow to use `actions-rust-lang/audit`.

  ### Notes to the reviewers

  The old [`actions-rs/audit-check`](https://github.com/actions-rs/audit-check) is no longer maintained.

  ### Checklists

  #### All Submissions:

  * [x] I've signed all my commits
  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md)
  * [x] I ran `cargo fmt` and `cargo clippy` before committing

Top commit has no ACKs.

Tree-SHA512: f876d6289ad1a3c87cd1820d2efc931f1284ac4ad7fc3e0400f5fcf7274c41d27c1d3f3fe173e258b7115a724bf424e0b9240358fa79f84cef5144256628951c