build(deps): bump websockets in /tests/ocpp-server in the major group

build(deps): bump websockets in /tests/ocpp-server in the major group

Bumps the major group in /tests/ocpp-server with 1 update: [websockets](https://github.com/python-websockets/websockets).

Updates `websockets` from 12.0 to 13.0
- [Release notes](https://github.com/python-websockets/websockets/releases)
- [Commits](https://github.com/python-websockets/websockets/compare/12.0...13.0)

---
updated-dependencies:
- dependency-name: websockets
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: major
...

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