Detect plantuml license correctly

[pombredanne]

See: https://raw.githubusercontent.com/plantuml/plantuml/refs/heads/master/README.md

## 📃 License

PlantUML is licensed under several licenses; you can choose the one that suits you best:

- [GPL license](https://www.gnu.org/licenses/gpl-3.0.html)
- [LGPL license](https://www.gnu.org/licenses/lgpl-3.0.html)
- [Apache license](https://www.apache.org/licenses/LICENSE-2.0)
- [Eclipse Public license](https://www.eclipse.org/legal/epl-2.0/)
- [MIT license](https://opensource.org/licenses/MIT)

For more information, please refer to the [PlantUML license FAQ](https://plantuml.com/en/faq#ddbc9d04378ee462) to help determine which license is appropriate for your use case.

[BharathC0]

@pombredanne please assign me

[DennisClark]

This one must be a World Record: a five-part disjunctive license expression!

I think that the resulting license expression should be:

in SPDX identifiers
(MIT OR Apache-2.0 OR EPL-2.0 OR LGPL-3.0-or-later OR GPL-3.0-or-later)

in SCTK keys
(mit OR apache-2.0 OR epl-2.0 OR lgpl-3.0-plus OR gpl-3.0-plus)