Explicitly install a Rust toolchain for cargo-outdated job

dtolnay · dtolnay · commit 4f0b72eb8455 · 2024-03-25T22:24:49.000-07:00
Debugging a recent cargo-outdated bug, it would have been nice not to
wonder whether a rustc version change in GitHub's runner image was a
contributing factor.
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -96,5 +96,6 @@ jobs:
     timeout-minutes: 45
     steps:
       - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
       - uses: dtolnay/install@cargo-outdated
       - run: cargo outdated --workspace --exit-code 1
