[roll third_party/pigweed] pw_polyfill/cstddef: Add missing constexpr specifiers

The std::byte shift operators were missing the constexpr
specifiers, this adds them back in.

For reference: https://en.cppreference.com/w/cpp/types/byte

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/78588

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 9198bc6dd7ee5d5..bce17aa55c71909
Roller-URL: https://ci.chromium.org/b/8824646703899442721
Cq-Cl-Tag: roller-builder:pigweed-sample-project-roller
Cq-Cl-Tag: roller-bid:8824646703899442721
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Ic6d0d217eb25c4321d89b3aab2d627bc4826f98f
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/sample_project/+/79300
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 9198bc6..bce17aa 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 9198bc6dd7ee5d5c607d110af8bc32daa5475292
+Subproject commit bce17aa55c71909e790cb1dc7b43128a51241c92