Skip some "tests/*/main.rkt" in drdr.
Skip some "tests/*/main.rkt" in drdr.

These files are invoking tests that are implemented in other files.

mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket