[roll third_party/pigweed] pw_build: Restore ._build_wheel for Python Pkgs

The new Python build system flag was inadvertently disabling the
._build_wheel targets for every python package. This was breaking the
pw_python_wheels template.

Also only add install_3p_deps as dep on python actions if the new
Python build system is enabled.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/94280

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: e2dcca1857dabf5..3feef6a3514a2e8
Roller-URL: https://ci.chromium.org/b/8814240071388532673
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8814240071388532673
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I09fd8e1a2eed346c827dc1bcb60e39f270cf0bef
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/94562
Commit-Queue: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
Bot-Commit: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index e2dcca1..3feef6a 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit e2dcca1857dabf5d9ff3e6bb55f5e8e3e06d2924
+Subproject commit 3feef6a3514a2e818c50ebc4d4329622b15b54fb