chore(deps): update guillaumefalourd/branch-exists action to v1.2 (#5041)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [GuillaumeFalourd/branch-exists](https://github.com/GuillaumeFalourd/branch-exists) | action | minor | `v1.1` → `v1.2` |

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### Release Notes

<details>
<summary>GuillaumeFalourd/branch-exists (GuillaumeFalourd/branch-exists)</summary>

### [`v1.2`](https://github.com/GuillaumeFalourd/branch-exists/releases/tag/v1.2)

[Compare Source](https://github.com/GuillaumeFalourd/branch-exists/compare/v1.1...v1.2)

Update actions/checkout to v6.0.2.

</details>

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### 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 is behind base branch, 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://github.com/renovatebot/renovate).
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Reviewed-on: #5041
Co-authored-by: Renovate Bot <renovate-bot@alexlebens.net>
Co-committed-by: Renovate Bot <renovate-bot@alexlebens.net>

.gitea/workflows/lint-test-docker.yaml

@@ -28,7 +28,7 @@ jobs:
       - name: Check Branch Exists
         id: check-branch-exists
         if: github.event_name == 'pull_request'
-        uses: GuillaumeFalourd/branch-exists@009290475dc3d75b5d7ec680c0c5b614b0d9855d # v1.1
+        uses: GuillaumeFalourd/branch-exists@650358876c774d6ccbd581b5553eb636dab79a97 # v1.2
         with:
           branch: "${{ github.base_ref }}"