Compress the blacklist of Scala.js tests.
Compress the blacklist of Scala.js tests.

We do not decompose by subdirectory anymore. This makes the list
shorter, and also makes sure that we do not forget top-level
directories.

sjrd/dotty,sjrd/dotty,lampepfl/dotty,lampepfl/dotty,dotty-staging/dotty,sjrd/dotty,dotty-staging/dotty,lampepfl/dotty,sjrd/dotty,dotty-staging/dotty,lampepfl/dotty,lampepfl/dotty,dotty-staging/dotty,sjrd/dotty,dotty-staging/dotty