chore(deps): bump dtolnay/rust-toolchain in the actions group

Bumps the actions group with 1 update: [dtolnay/rust-toolchain](https://github.com/dtolnay/rust-toolchain).


Updates `dtolnay/rust-toolchain` from 3c5f7ea28cd621ae0bf5283f0e981fb97b8a7af9 to 67ef31d5b988238dd797d409d6f9574278e20537
- [Release notes](https://github.com/dtolnay/rust-toolchain/releases)
- [Commits](dtolnay/rust-toolchain@3c5f7ea...67ef31d)

---
updated-dependencies:
- dependency-name: dtolnay/rust-toolchain
  dependency-version: 67ef31d5b988238dd797d409d6f9574278e20537
  dependency-type: direct:production
  dependency-group: actions
...

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

Author: dependabot[bot]

.github/workflows/mirror.yml

@@ -141,7 +141,7 @@ jobs:
           fetch-depth: 0
 
       - name: Setup Rust
-        uses: dtolnay/rust-toolchain@3c5f7ea28cd621ae0bf5283f0e981fb97b8a7af9 # stable
+        uses: dtolnay/rust-toolchain@67ef31d5b988238dd797d409d6f9574278e20537 # stable
         with:
           toolchain: stable