main: enable args_split unit tests on Windows
main: enable args_split unit tests on Windows

These tests work correctly on Windows as well, so remove the check that
made them only run on Linux.

BUG=b:238361778
TEST=tools/dev_container tools/run_tests --platform=mingw64

Change-Id: I775cfe66f3324aee3b83c9deeb93a019f4b07296
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/4032428
Commit-Queue: Daniel Verkamp <72bc170b46ec491f7bdd4359a1c0bfed274de40c@chromium.org>
Reviewed-by: Vikram Auradkar <50abc1d85bedfd527fc7dee23f4819d1f0d946ec@google.com>

google/crosvm,google/crosvm,google/crosvm,google/crosvm