build(deps): bump actions-rust-lang/setup-rust-toolchain

Bumps [actions-rust-lang/setup-rust-toolchain](https://github.com/actions-rust-lang/setup-rust-toolchain) from 1.15.2 to 1.16.0.
- [Release notes](https://github.com/actions-rust-lang/setup-rust-toolchain/releases)
- [Changelog](https://github.com/actions-rust-lang/setup-rust-toolchain/blob/main/CHANGELOG.md)
- [Commits](actions-rust-lang/setup-rust-toolchain@1780873...2b1f5e9)

---
updated-dependencies:
- dependency-name: actions-rust-lang/setup-rust-toolchain
  dependency-version: 1.16.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/audit.yml

@@ -35,7 +35,7 @@ jobs:
           persist-credentials: false
 
       - name: Install Rust toolchain and configure cache
-        uses: actions-rust-lang/setup-rust-toolchain@1780873c7b576612439a134613cc4cc74ce5538c # v1
+        uses: actions-rust-lang/setup-rust-toolchain@2b1f5e9b395427c92ee4e3331786ca3c37afe2d7 # v1
         with:
           toolchain: stable
           cache: true