Bug: MSRV is defacto 1.81.0 while advertised as 1.70.0

[Wumpf]

Describe the bug

MSRV is advertised as 1.70.0:
https://github.com/EmbarkStudios/cargo-deny/blob/main/Cargo.toml#L18

However, in 0.16.2 one of the dependencies causes a higher required rust version.

Running in an environment with rust-toolchain file yields:

 error: failed to compile `cargo-deny v0.16.2`, intermediate artifacts can be found at `/tmp/cargo-installmuEfF3`.
To reuse those artifacts with a future compilation, set the environment variable `CARGO_TARGET_DIR` to that path.

Caused by:
  rustc 1.79.0 is not supported by the following package:
    twox-hash@2.0.1 requires rustc 1.81

Didn't hit this with 0.16.1 - the dependency updates in 0.16.2 caused this

To reproduce

• create a rust toolchain file with

[toolchain]
channel = "1.79.0"

• install cargo deny: cargo install --locked cargo-deny@0.16.2

cargo-deny version

0.16.2

What OS were you running cargo-deny on?

None

Additional context

No response