[roll third_party/pigweed] pw_protobuf: Break the ambiguity for spans in generated code

Some std::span implementations has an ambiguity in the resolving
(ptr, 0) span construction. This CL adds explicit size_t for the second
arg to avoid it.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/99285

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 0c47c3378fca1b8..60924a144f6a32d
Roller-URL: https://ci.chromium.org/b/8810527271638416161
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8810527271638416161
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Iac3b98833c16cbfc6c220cebfd7d08a3f6c56c03
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/99534
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 0c47c33..60924a1 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 0c47c3378fca1b86f1760bbae6b8d2bade227ce2
+Subproject commit 60924a144f6a32d4bcf25c726e5582085d532171