chore: bump up actions/labeler action to v6 (#14552)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/labeler](https://redirect.github.com/actions/labeler) |
action | major | `v5` → `v6` |

---

### Release Notes

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

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

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

</details>

---

### Configuration

📅 **Schedule**: Branch creation - At any time (no schedule defined),
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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.github/workflows/auto-labeler.yml

@@ -14,4 +14,4 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
-      - uses: actions/labeler@v5
+      - uses: actions/labeler@v6