roll: third_party/pigweed pw_thread: Generic thread creation

Implement the cross-platform thread creation API proposed in SEED-0128.

Fixes: b/373524851
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/255065
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Original-Revision: e9d4e4d30b4a49b2ca4dba88656dc660b0a0bcaf

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 1a98c3d9725b41..e9d4e4d30b4a49
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8724965291432114033
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I2973d370dd5dc910730cc2ead32dbb0bbe64695a
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/262232
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 1a98c3d..e9d4e4d 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 1a98c3d9725b4178148a354b917f15d86fc374b5
+Subproject commit e9d4e4d30b4a49b2ca4dba88656dc660b0a0bcaf