[roll third_party/pigweed] pw_watch: Fix watchdog version and ignore project dirs

Pins the watchdog version to preserve functionality on MacOS, and
adds  the commonly ignored directories that fall under the
PW_PROJECT_ROOT, in addition to PW_ROOT. This makes life easier for
downstream projects, which likely want to ignore the same directories.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/38180

third_party/pigweed Rolled-Commits: d731b35033e06dc..8592008642e8675
Roller-URL: https://ci.chromium.org/b/8852485953561106496
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8852485953561106496
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Iefe001e5b8db8c8b0f1d452276533b65731f9f72
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/38280
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 d731b35..8592008 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit d731b35033e06dc0c826daf50f9b18714e9f7bc2
+Subproject commit 8592008642e8675a0360c673e632441b80be789c