chore(deps): update actions/checkout action to v4 (GoogleCloudPlatfor…

…m#921)

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This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/checkout](https://github.com/actions/checkout) | action |
major | `v3` -> `v4` |

---

> [!WARNING]
> Some dependencies could not be looked up. Check the warning logs for
more information.

---

### Release Notes

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

###
[`v4`](https://github.com/actions/checkout/blob/HEAD/CHANGELOG.md#v417)

[Compare Source](https://github.com/actions/checkout/compare/v3...v4)

- Bump the minor-npm-dependencies group across 1 directory with 4
updates by [@&#8203;dependabot](https://github.com/dependabot) in
[actions/checkout#1739
- Bump actions/checkout from 3 to 4 by
[@&#8203;dependabot](https://github.com/dependabot) in
[actions/checkout#1697
- Check out other refs/\* by commit by
[@&#8203;orhantoy](https://github.com/orhantoy) in
[actions/checkout#1774
- Pin actions/checkout's own workflows to a known, good, stable version.
by [@&#8203;jww3](https://github.com/jww3) in
[actions/checkout#1776

</details>

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.github/workflows/assign-issue.yaml

@@ -12,7 +12,7 @@ jobs:
 
     steps:
       - name: Checkout Repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Set up Python
         uses: actions/setup-python@v4