[Fuzzer] Mark test as unsupported on Windows

bf932867acc003f4dd5bf4d8b295f764a3a85c91 enabled this test to run on
Windows again, but it started failing due to the use of ulimit.
Redisable it on Windows.

https://lab.llvm.org/buildbot/#/builders/107/builds/16280

GitOrigin-RevId: ed9bc1ccd4036555fbe5f1f2433fe672d0f83d4e