JDKInternalAPIsTest is defined twice

[llxia]

JDKInternalAPIsTest is defined twice in playlist.xml:

https://github.com/AdoptOpenJDK/openjdk-tests/blob/04692d90e704b19433ab608cadf1751e10bda60a/systemtest/modularity/playlist.xml#L340

https://github.com/AdoptOpenJDK/openjdk-tests/blob/04692d90e704b19433ab608cadf1751e10bda60a/systemtest/modularity/playlist.xml#L170

They seem to be a duplication. If so, we need to remove one of them.

[llxia]

fyi @AndreOikawa