[roll third_party/pigweed] misc: Update non-type template parameter style

Switch non-type template parameters to kConstant style in accordance
with https://pigweed.dev/docs/style_guide.html.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/56829

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 6a10095b7b61ef2..b8c67ac97bec39a
Roller-URL: https://ci.chromium.org/b/8839071892343777120
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8839071892343777120
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I9f22726309e212b6ccc0eb810542c938559469b0
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/56921
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 6a10095..b8c67ac 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 6a10095b7b61ef2d3b7d185698b308bac2356c4d
+Subproject commit b8c67ac97bec39a50ead4f976f7754d53daad500