roll: third_party/pigweed b6de265..21933c6 (3 commits)

21933c6:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/248638 pw_async2: Accept alignment in CoroPromiseType::operator new
5b608da:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/248637 pw_build: Restore layering_check workaround for pw_facade
ef6ae0d:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/234930 pw_string: Stringify time types

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: b6de26528a8add..21933c60384c25
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8731330671753322385
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: If360e094d26fc5050ed57b02edd330941b6e299a
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/248872
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 b6de265..21933c6 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit b6de26528a8add6f9d18cff0dd7709d51a606ad5
+Subproject commit 21933c60384c25d73dba60c90e74cc44d2a446de