impl: Update actions/checkout action to v4.2.1 (#1186)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/checkout](https://redirect.github.com/actions/checkout) |
action | patch | `v4.2.0` -> `v4.2.1` |

---

### Release Notes

<details>
<summary>actions/checkout (actions/checkout)</summary>

###
[`v4.2.1`](https://redirect.github.com/actions/checkout/blob/HEAD/CHANGELOG.md#v421)

[Compare
Source](https://redirect.github.com/actions/checkout/compare/v4.2.0...v4.2.1)

- Check out other refs/\* by commit if provided, fall back to ref by
[@&#8203;orhantoy](https://redirect.github.com/orhantoy) in
[https://github.com/actions/checkout/pull/1924](https://redirect.github.com/actions/checkout/pull/1924)

</details>

---

### Configuration

📅 **Schedule**: Branch creation - "every weekend" (UTC), Automerge - At
any time (no schedule defined).

🚦 **Automerge**: Disabled by config. Please merge this manually once you
are satisfied.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the
rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update
again.

---

- [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check
this box

---

This PR was generated by [Mend Renovate](https://mend.io/renovate/).
View the [repository job
log](https://developer.mend.io/github/slsa-framework/slsa).

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzOC4xMTUuMSIsInVwZGF0ZWRJblZlciI6IjM4LjExNS4xIiwidGFyZ2V0QnJhbmNoIjoibWFpbiIsImxhYmVscyI6W119-->

Signed-off-by: Mend Renovate <bot@renovateapp.com>

.github/workflows/lint.yml

@@ -6,7 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout
-      uses: actions/checkout@d632683dd7b4114ad314bca15554477dd762a938 # v4.2.0
+      uses: actions/checkout@eef61447b9ff4aafe5dcd4e0bbf5d482be7e7871 # v4.2.1
     - name: Setup Node
       uses: actions/setup-node@0a44ba7841725637a19e28fa30b79a866c81b0a6 # v4.0.4
     - run: npm ci --ignore-scripts