[roll third_party/pigweed] pw_kvs: Restore implicitly deleted constructor

No-Docs-Update-Reason: Compiler update bugfix
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/47540

third_party/pigweed Rolled-Commits: 2a4533c7aa4006e..c3ea4062036d747
Roller-URL: https://ci.chromium.org/b/8845602332817327840
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8845602332817327840
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I203c9ffed02419c5e1d1882faea677ccd457e777
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/47561
Reviewed-by: 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 2a4533c..c3ea406 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 2a4533c7aa4006e481d2615c1611d8d1d5b34ac3
+Subproject commit c3ea4062036d747c479055c9d69998567843ceed