Revert "Roll the latest args package into the SDK repo."

This reverts commit 9906fabaa0c5bf60a959c9ccf523c0398b671ad7.

Reason for revert: Causes regressions in google3 (likely need internal CL to get new args package in third party), see https://ci.chromium.org/ui/p/dart/builders/ci.sandbox/google/3073/overview

Original change's description:
> Roll the latest args package into the SDK repo.
>
> Change-Id: Ie464e5c01f34a101103d16ff108b6b9eb80fbd4b
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/174485
> Reviewed-by: Nate Bosch <nbosch@google.com>
> Commit-Queue: Bob Nystrom <rnystrom@google.com>
> Auto-Submit: Bob Nystrom <rnystrom@google.com>

TBR=rnystrom@google.com,nbosch@google.com

Change-Id: I9d3091d1631a145cd8b37317cc2e381762e5a46a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/174646
Reviewed-by: Tess Strickland <sstrickl@google.com>
Commit-Queue: Tess Strickland <sstrickl@google.com>