[roll third_party/pigweed] pw_assert_log: add missing check_backend.impl group

Bugfix, this was missing from this change:
https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/96741

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/97908

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 1b316704ba4b9ec..67bc89cdda8c663
Roller-URL: https://ci.chromium.org/b/8811423579774630145
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8811423579774630145
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I1d3933d229fc957afa2c20f5195fad75ed474ef1
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/97957
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 1b31670..67bc89c 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 1b316704ba4b9ec57704b843723c512d62b9949b
+Subproject commit 67bc89cdda8c663b1983c6215f14e8db6a19a328