roll: third_party/pigweed pw_sys_io: Clean up for-migration-only alias

Original-Bug: 328679085
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/238431
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Original-Revision: 06f958a5ab8a2c9d30ac07fabdf28c2ecff147a6

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 1d143bbc5b00ac..06f958a5ab8a2c
Roller-URL: https://ci.chromium.org/b/8735330407085698305
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Ibc976132b9bfd4663d6ec8f83d7e720467e68c8d
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/238858
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 1d143bb..06f958a 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 1d143bbc5b00ac5f778977493831d34a19a637d4
+Subproject commit 06f958a5ab8a2c9d30ac07fabdf28c2ecff147a6