clippy: fix on nightly toolchain

[jsha]

Right now on the nightly toolchain, clippy gives an error. This doesn't block merges because we mark the nightly clippy check as optional, and only require the clippy check for a specified toolchain version.

I've filed #333 to address the error. In this PR I disable that particular clippy lint and bump the required toolchain version to 1.73.0.

[cpu]

Thanks for the quick fix 👍

[jsha]

In CI, was getting:

error: could not download nonexistent rust version `1.73.0-x86_64-unknown-linux-gnu`: could not download file from 'https://static.rust-lang.org/dist/rust-1.73.0-x86_64-unknown-linux-gnu.tar.gz.sha256' to '/home/runner/.rustup/tmp/ez9sp9x7zg6d3ws7_file': http request returned an unsuccessful status code: 404

I realized I pulled the latest version from my nightly toolchain locally, which of course is not a released version. Bumped it down to 1.72.0.

[jsha]

Heh, and 1.71 is still in beta. Bumped it further down to 1.70. Also I realized we have the same fixed version for the cargo fmt check so I bumped that as well.

[jsha]

Now that version 1.70.0 is running for the "required" clippy, I get this:

error: unknown lint: `clippy::arc_with_non_send_sync`
 --> src/lib.rs:5:10
  |
5 | #![allow(clippy::arc_with_non_send_sync)]
  |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `-D unknown-lints` implied by `-D warnings`

In the latest revision, I turn on -A unknown-lints for the required clippy (1.70.0) only. This allows unrecognized lints in the older clippy; but they will trigger an advisory error in the newer clippy (even though it won't block merging).

[cpu]

In the latest revision, I turn on -A unknown-lints for the required clippy (1.70.0) only. This allows unrecognized lints in the older clippy; but they will trigger an advisory error in the newer clippy (even though it won't block merging).

Sounds like a reasonable workaround. Thanks for chasing this down.