[roll third_party/pigweed] pw_third_party: update protobuf to build google.protobuf

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/60186

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 6d7317260b3bc08..cd66a7460905b29
Roller-URL: https://ci.chromium.org/b/8836594524978652801
Cq-Cl-Tag: roller-builder:pigweed-sample-project-roller
Cq-Cl-Tag: roller-bid:8836594524978652801
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I24ea0212847fc5a0d5aa181a6382f1de3c2b64c2
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/sample_project/+/60323
Bot-Commit: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
Commit-Queue: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 6d73172..cd66a74 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 6d7317260b3bc088860290d5611558d1e74d7af6
+Subproject commit cd66a7460905b2905769acc3c80a0dd3d7b4a856