chore(deps): update actions/checkout action to v6 (#5)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/checkout](https://github.com/actions/checkout) | action | major | `v3` -> `v6` |

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### Release Notes

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

### [`v6`](https://github.com/actions/checkout/blob/HEAD/CHANGELOG.md#v600)

[Compare Source](https://github.com/actions/checkout/compare/v5...v6)

- Persist creds to a separate file by [@&#8203;ericsciple](https://github.com/ericsciple) in [#&#8203;2286](https://github.com/actions/checkout/pull/2286)
- Update README to include Node.js 24 support details and requirements by [@&#8203;salmanmkc](https://github.com/salmanmkc) in [#&#8203;2248](https://github.com/actions/checkout/pull/2248)

### [`v5`](https://github.com/actions/checkout/blob/HEAD/CHANGELOG.md#v501)

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

- Port v6 cleanup to v5 by [@&#8203;ericsciple](https://github.com/ericsciple) in [#&#8203;2301](https://github.com/actions/checkout/pull/2301)

### [`v4`](https://github.com/actions/checkout/blob/HEAD/CHANGELOG.md#v431)

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

- Port v6 cleanup to v4 by [@&#8203;ericsciple](https://github.com/ericsciple) in [#&#8203;2305](https://github.com/actions/checkout/pull/2305)

</details>

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Reviewed-on: #5
Reviewed-by: t.behrendt <t.behrendt@noreply.localhost>
Co-authored-by: Renovate Bot <renovate@t00n.de>
Co-committed-by: Renovate Bot <renovate@t00n.de>

.gitea/workflows/weekly.yaml

@@ -12,7 +12,7 @@ jobs:
       - linux_amd64
     steps:
       - name: Checkout code
-        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
       - name: Setup Go
         uses: actions/setup-go@d35c59abb061a4a6fb18e82ac0862c26744d6ab5 # v5
         with: