Bump mockito-core from 2.27.0 to 2.28.1 (#5008)
Bump mockito-core from 2.27.0 to 2.28.1 (#5008)

Bumps [mockito-core](https://github.com/mockito/mockito) from 2.27.0 to 2.28.1.
- [Release notes](https://github.com/mockito/mockito/releases)
- [Commits](https://github.com/mockito/mockito/compare/v2.27.0...v2.28.1)
JabRef/jabref,sauliusg/jabref,sauliusg/jabref,JabRef/jabref,JabRef/jabref,sauliusg/jabref,Siedlerchr/jabref,zellerdev/jabref,zellerdev/jabref,Siedlerchr/jabref,zellerdev/jabref,Siedlerchr/jabref,zellerdev/jabref,JabRef/jabref,zellerdev/jabref,Siedlerchr/jabref,sauliusg/jabref