roll: third_party/pigweed c1df27e..21fa95f (3 commits)

21fa95f:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/330912 pw_compilation_testing: Improve NC test build errors
bd8ccac:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/332332 zephyr: Update OWNERS
967ad18:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/330412 pw_metric: Introduce PwpbStreamingMetricWriter for zero-copy encoding

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: c1df27e813d808..21fa95fd20a6fa
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8701089072873536865
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I5c339c983877bd649a6d7d60d25104f83ed67d6a
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/332432
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Bot-Commit: 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 c1df27e..21fa95f 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit c1df27e813d80878942f62d653dcabfde2c0897f
+Subproject commit 21fa95fd20a6fa54126d5e254692a034bbb72a56