[MLIR][Bazel] correctly fix bazel build after 59e74a0 (#160539)
https://github.com/llvm/llvm-project/pull/160508 wasn't the correct fix
- the fix just disabled the test because
https://github.com/llvm/llvm-project/blob/59e74a0749203998b3e5fd9bc6525de148db28ab/mlir/test/Examples/standalone/lit.local.cfg#L18
is now always `False` (`if not "0"` is always `False`). This PR is the
correct fix.