roll: pigweed, pw_toolchain: pw_system: pw_system:async

- Introduce a version of pw_system that uses async comms.
- Add a pw_system example that uses a TCP port for comms.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/216239
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>

https://pigweed.googlesource.com/pigweed/pigweed
pigweed, pw_toolchain Rolled-Commits: edf7501f5d03e8f..befcb91b39880a5
Roller-URL: https://ci.chromium.org/b/8743995885328838497
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I388c97ccf2b462fec79e7f1ab7aff29b2d6268f9
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/quickstart/bazel/+/218458
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
diff --git a/WORKSPACE b/WORKSPACE
index 52575d2..6f4d9b9 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -84,8 +84,8 @@
     name = "pigweed",
     # ROLL: Warning: this entry is automatically updated.
     # ROLL: Last updated 2024-06-27.
-    # ROLL: By https://cr-buildbucket.appspot.com/build/8744017057100871281.
-    commit = "edf7501f5d03e8fb877e92f76defc63784d0171e",
+    # ROLL: By https://cr-buildbucket.appspot.com/build/8743995885328838497.
+    commit = "befcb91b39880a524eee664d10fa5df273d138d6",
     remote = "https://pigweed.googlesource.com/pigweed/pigweed.git",
 )
 
@@ -93,8 +93,8 @@
     name = "pw_toolchain",
     # ROLL: Warning: this entry is automatically updated.
     # ROLL: Last updated 2024-06-27.
-    # ROLL: By https://cr-buildbucket.appspot.com/build/8744017057100871281.
-    commit = "edf7501f5d03e8fb877e92f76defc63784d0171e",
+    # ROLL: By https://cr-buildbucket.appspot.com/build/8743995885328838497.
+    commit = "befcb91b39880a524eee664d10fa5df273d138d6",
     remote = "https://pigweed.googlesource.com/pigweed/pigweed.git",
     strip_prefix = "pw_toolchain_bazel",
 )