Update https://data.forgejo.org/actions/setup-forgejo action to v3.1.0 (#1402)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [https://data.forgejo.org/actions/setup-forgejo](https://code.forgejo.org/actions/setup-forgejo) | action | minor | `v3.0.7` → `v3.1.0` |

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### Release Notes

<details>
<summary>actions/setup-forgejo (https://data.forgejo.org/actions/setup-forgejo)</summary>

### [`v3.1.0`](https://code.forgejo.org/actions/setup-forgejo/compare/v3.0.7...v3.1.0)

[Compare Source](https://code.forgejo.org/actions/setup-forgejo/compare/v3.0.7...v3.1.0)

</details>

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### Configuration

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Reviewed-on: https://code.forgejo.org/forgejo/end-to-end/pulls/1402
Reviewed-by: Mathieu Fenniak <mfenniak@noreply.code.forgejo.org>
Co-authored-by: Renovate Bot <bot@kriese.eu>
Co-committed-by: Renovate Bot <bot@kriese.eu>

.forgejo/prepare-end-to-end/action.yml

@@ -15,7 +15,7 @@ runs:
             /usr/local/bin/garage
           key: S3
 
-      - uses: https://data.forgejo.org/actions/setup-forgejo@v3.0.7
+      - uses: https://data.forgejo.org/actions/setup-forgejo@v3.1.0
         with:
           install-only: true
       - run: forgejo-binary.sh ensure_user forgejo