[roll third_party/pigweed] pw_router: Local per-packet parsers

This changes the StaticRouter API to take a PacketParser with each call
to RoutePacket rather than as a member. This PacketParser instance is
then forwarded to router egresses in place of the metadata struct (which
is removed altogether).

This has several benefits:

  1. Different formats of packets can be sent through the same router.
  2. No internal synchronization is required as there are no longer any
     shared resources.
  3. Users can forward custom data to router egresses instead of having
     to use the set of fields defined by the router.

Original-Requires: pigweed-internal:19780
Original-Requires: pigweed-internal:19781
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/75960

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: b402c558ea6c269..46f74e074f27392
Roller-URL: https://ci.chromium.org/b/8827104881367555057
Cq-Cl-Tag: roller-builder:pigweed-sample-project-roller
Cq-Cl-Tag: roller-bid:8827104881367555057
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Ia757cc8243e8a0a95e334ea172e090fbccf95de9
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/sample_project/+/76240
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 b402c55..46f74e0 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit b402c558ea6c2698559ffcd34ff4246eec55a04f
+Subproject commit 46f74e074f27392574e828ce36e8b9041095dc0a