renovatebot(deps): update github artifact actions (major)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/download-artifact](https://redirect.github.com/actions/download-artifact) | action | major | `v5` -> `v6` |
| [actions/upload-artifact](https://redirect.github.com/actions/upload-artifact) | action | major | `v4` -> `v5` |

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

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### Release Notes

<details>
<summary>actions/download-artifact (actions/download-artifact)</summary>

### [`v6`](https://redirect.github.com/actions/download-artifact/compare/v5...v6)

[Compare Source](https://redirect.github.com/actions/download-artifact/compare/v5...v6)

</details>

<details>
<summary>actions/upload-artifact (actions/upload-artifact)</summary>

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

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

</details>

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### Configuration

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

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

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👻 **Immortal**: This PR will be recreated if closed unmerged. Get [config help](https://redirect.github.com/renovatebot/renovate/discussions) if that's undesired.

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This PR has been generated by [Renovate Bot](https://redirect.github.com/renovatebot/renovate).
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Author: apereocas-bot