build(deps): bump dtolnay/rust-toolchain (#1204)

Author: dependabot[bot]

.github/workflows/mutation-testing.yml

@@ -53,7 +53,7 @@ jobs:
           persist-credentials: false
           submodules: recursive
 
-      - uses: dtolnay/rust-toolchain@56f84321dbccf38fb67ce29ab63e4754056677e0  # stable
+      - uses: dtolnay/rust-toolchain@f7ccc83f9ed1e5b9c81d8a67d7ad1a747e22a561  # stable
         with:
           toolchain: stable