test(deps): update dependency junit:junit to v4.13.1 (#1209)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [junit:junit](http://junit.org) ([source](https://github.com/junit-team/junit4)) | patch | `4.13` -> `4.13.1` |

---

### Renovate configuration

:date: **Schedule**: At any time (no schedule defined).

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

:recycle: **Rebasing**: Renovate will not automatically rebase this PR, because other commits have been found.

:no_bell: **Ignore**: Close this PR and you won't be reminded about these updates again.

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box

---

This PR has been generated by [WhiteSource Renovate](https://renovate.whitesourcesoftware.com). View repository job log [here](https://app.renovatebot.com/dashboard#github/googleapis/gax-java).