[roll third_party/pigweed] pw_work_queue: Adds a single threaded work queue

Adds a pw::work_queue::WorkQueue concept which is comprised of a
queue of pw::Functions and a singular thread which drains the
queue.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/56269

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 1a4478bc3c621ce..04f1292499f3840
Roller-URL: https://ci.chromium.org/b/8839038394362709201
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8839038394362709201
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I7e6e22997980ba60db272160c06d3aa06fba478c
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/56984
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 1a4478b..04f1292 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 1a4478bc3c621ce74f192dac3a0663cec71b3f88
+Subproject commit 04f1292499f3840672d42824c4452d9175cc11c4