[dart/fuzzer] Disable jit-opt modes
[dart/fuzzer] Disable jit-opt modes

Rationale:
None of the jit-opt-xxx modes gives any useful
information while the flag is not stable.

https://github.com/dart-lang/sdk/issues/35196

Change-Id: I103931a21a1d9d8293b3044f00e9a73c0f6fe6f5
Reviewed-on: https://dart-review.googlesource.com/c/84827
Reviewed-by: Alexander Thomas <29642742b6693024c89de8232f2e2542cf7eedf7@google.com>
Commit-Queue: Aart Bik <293afa0533434225484ba3f9bf2859340baba6ea@google.com>

dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk