Update actions/checkout action to v5 (#111)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/checkout](https://redirect.github.com/actions/checkout) | action | major | `v4` -> `v5` |

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### Release Notes

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

### [`v5`](https://redirect.github.com/actions/checkout/compare/v4...v5)

[Compare Source](https://redirect.github.com/actions/checkout/compare/v4...v5)

</details>

---

### Configuration

📅 **Schedule**: Branch creation - "every weekday after 9am before 5pm" in timezone America/New_York, Automerge - At any time (no schedule defined).

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

â™» **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 has been generated by [Renovate Bot](https://redirect.github.com/renovatebot/renovate).
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diff --git a/.github/workflows/automation-autosquash.yml b/.github/workflows/automation-autosquash.yml
index 53e897a..f2107d6 100644
--- a/.github/workflows/automation-autosquash.yml
+++ b/.github/workflows/automation-autosquash.yml
@@ -27,7 +27,7 @@
           app-id: ${{ secrets.THM_AUTOMATION_APP_ID }}
           private-key: ${{ secrets.THM_AUTOMATION_PRIVATE_KEY }}
       - if: github.event.pull_request.head.repo.full_name == 'theoremlp/rules_mypy'
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - if: github.event.pull_request.head.repo.full_name == 'theoremlp/rules_mypy'
         uses: theoremlp/autosquash@v1
         with:
diff --git a/.github/workflows/automation-update-requirements.yml b/.github/workflows/automation-update-requirements.yml
index 3ab15cc..7aebbc3 100644
--- a/.github/workflows/automation-update-requirements.yml
+++ b/.github/workflows/automation-update-requirements.yml
@@ -18,7 +18,7 @@
         with:
           app-id: ${{ secrets.THM_AUTOMATION_APP_ID }}
           private-key: ${{ secrets.THM_AUTOMATION_PRIVATE_KEY }}
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           token: ${{ steps.app-token.outputs.token }}
           ref: ${{ github.event.pull_request.head.sha }}
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f8f4ab7..14ab2bc 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -17,7 +17,7 @@
         os: ["ubuntu-latest"]
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: bazel-contrib/setup-bazel@0.15.0
         with:
           repository-cache: true