Add 'cargo-audit' to the CI

[elBoberido]

I think a first step in this direction would be to add an automatic audit using https://crates.io/crates/cargo-audit

Extending the CI file wouldn't be that hard either:

iox2_cargo_fmt_and_clippy_template: &IOX2_CARGO_FMT_AND_CLIPPY
  cargo_fmt_and_clippy_script:
    - cargo fmt --all -- --check
    - cargo clippy -- -D warnings
    - cargo audit

Originally posted by @hydroid7 in https://github.com/eclipse-iceoryx/iceoryx2/issues/6#issuecomment-1857554174

[hydroid7]

Ok, so I opened a PR, but I'm really no expert with Cirrus CI.