[roll third_party/pigweed] targets/rp2040: Replace rp2040 target with rp2040_pw_system

Merges the rp2040_pw_system target into rp2040, introducing a RPC-based
test runner to maintain testing parity.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/192516

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 72840bdfdc5b67d..a41e6b8905827ef
Roller-URL: https://ci.chromium.org/b/8755889513994051281
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I525c79e32e2d0e79a2ab3035324765a1e9c7a854
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/192946
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 72840bd..a41e6b8 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 72840bdfdc5b67d2cfcc05c5dc1c4f22fd7860a2
+Subproject commit a41e6b8905827ef9028a057af9983e53d78abb28