chore(deps): Update actions/checkout action to v4 (#261)

This PR contains the following updates:

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

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### Release Notes

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

### [`v4`](https://togithub.com/actions/checkout/blob/HEAD/CHANGELOG.md#v422)

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

-   `url-helper.ts` now leverages well-known environment variables by [@&#8203;jww3](https://togithub.com/jww3) in [https://github.com/actions/checkout/pull/1941](https://togithub.com/actions/checkout/pull/1941)
-   Expand unit test coverage for `isGhes` by [@&#8203;jww3](https://togithub.com/jww3) in [https://github.com/actions/checkout/pull/1946](https://togithub.com/actions/checkout/pull/1946)

</details>

---

### Configuration

📅 **Schedule**: Branch creation - "before 4am on the first day of the month" (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

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This PR has been generated by [Renovate Bot](https://togithub.com/renovatebot/renovate).
<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzNy40NDAuNyIsInVwZGF0ZWRJblZlciI6IjM3LjQ0MC43IiwidGFyZ2V0QnJhbmNoIjoibWFpbiIsImxhYmVscyI6W119-->

Author: cq-bot

.github/workflows/gen-client.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           token: ${{ secrets.GH_CQ_BOT }}
 

.github/workflows/lint_golang.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: actions/setup-go@v4
         with:
           go-version-file: go.mod

.github/workflows/unittest.yml

@@ -17,7 +17,7 @@ jobs:
         os: [ubuntu-latest, macos-latest, windows-latest]
     steps:
       - name: Check out code into the Go module directory
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Set up Go 1.x
         uses: actions/setup-go@v4
         with: