roll: third_party/pigweed 2 commits

ac64a18ef887e4b bazel: Move toolchain registration to MODULE.bazel
00d99767eb5ad66 bazel: Enable bzlmod

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 4f0412dae17b20a..ac64a18ef887e4b
Roller-URL: https://ci.chromium.org/b/8741662381886069041
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I3e1ccf65b2f25def37592afd482ebf7256a5ae7c
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/225511
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 4f0412d..ac64a18 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 4f0412dae17b20affc33d7162d584175861524be
+Subproject commit ac64a18ef887e4ba2387ed217aafa2dc45e201e0