Bump actions/checkout from 4.2.0 to 4.2.1

Bumps [actions/checkout](https://github.com/actions/checkout) from 4.2.0 to 4.2.1.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@d632683...eef6144)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/main.yml

@@ -12,7 +12,7 @@ jobs:
       matrix:
         rust: [stable, beta, nightly]
     steps:
-      - uses: actions/checkout@d632683dd7b4114ad314bca15554477dd762a938 # v4.2.0
+      - uses: actions/checkout@eef61447b9ff4aafe5dcd4e0bbf5d482be7e7871 # v4.2.1
       - name: Install Rust ${{ matrix.rust }}
         run: |
           rustup self update
@@ -26,7 +26,7 @@ jobs:
     name: Rustfmt
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@d632683dd7b4114ad314bca15554477dd762a938 # v4.2.0
+      - uses: actions/checkout@eef61447b9ff4aafe5dcd4e0bbf5d482be7e7871 # v4.2.1
       - name: Install Rust Stable
         run: |
           rustup update stable