[roll third_party/pigweed] pw_unit_test: Install python module before running

Ensures the pw_unit_test module is installed before running the test
runner script from the module.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/77186

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 26bc5a85a671265..2a0d4d58330bd4b
Roller-URL: https://ci.chromium.org/b/8825664143938651329
Cq-Cl-Tag: roller-builder:pigweed-sample-project-roller
Cq-Cl-Tag: roller-bid:8825664143938651329
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I1fcee71e69c82b5a90783344801eea543ed66b6c
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/sample_project/+/77517
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 26bc5a8..2a0d4d5 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 26bc5a85a671265aaf87cb84f36948947c1b67a0
+Subproject commit 2a0d4d58330bd4b2c120d2db8713b392e40cc342