[roll third_party/pigweed] pw_env_setup: deactivate clears PW_BRANDING_BANNER

Clear PW_BRANDING_BANNER in 'deactivate'.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/71780

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 40bfc43d01a6c41..e23423ef3e3acef
Roller-URL: https://ci.chromium.org/b/8828848404928822705
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8828848404928822705
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I36df676190166774a6bfdaae71dc0bacc21f4cab
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/71840
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 40bfc43..e23423e 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 40bfc43d01a6c410e8010fa014bb469c8364f35f
+Subproject commit e23423ef3e3acef6c12b124626d7107a0e0b0666