roll: third_party/pigweed: bazel: Modernize pip deps style (2)

Followup to http://pwrev.dev/223871.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/224316
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 4786d7910a0892f..d39a9561840c8fe
Roller-URL: https://ci.chromium.org/b/8741944197132746225
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Ic2744d0758cbb2f8be8c527dec8004d1516b7033
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/225111
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
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 4786d79..d39a956 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 4786d7910a0892fb163fde14c7abddfef890620f
+Subproject commit d39a9561840c8fe5931ee4d9ca848bf1acf6eca4