Bump mockito-core from 3.5.13 to 3.5.15

Bumps [mockito-core](https://github.com/mockito/mockito) from 3.5.13 to 3.5.15.
- [Release notes](https://github.com/mockito/mockito/releases)
- [Commits](https://github.com/mockito/mockito/compare/v3.5.13...v3.5.15

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>