[roll third_party/pigweed] pw_web: Add disconnect() method to WebSerialTransport

Also fix build and test errors and release a new NPM patch.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/156471

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 710c74a28e98257..4cb8e20663f29e6
Roller-URL: https://ci.chromium.org/b/8775188073904044961
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I4b9ad3f140bd48c5ec176a0d9261ff4a7ede6e00
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/156871
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 710c74a..4cb8e20 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 710c74a28e982576b3b6e19e567f2a6a38e1b31a
+Subproject commit 4cb8e20663f29e67574d7d33974c58b86b3baf22