[roll third_party/pigweed] pw_env_setup: Update json formatting

Update json formatting to what the roller will output so the next roll
only changes relevant lines.

See pwrev/46402 for what a test roll does to the formatting. This CL is
that CL minus the host tools change.

Original-Bug: 385
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/46500

third_party/pigweed Rolled-Commits: 653792bed324d66..42f03409a9ca2d3
Roller-URL: https://ci.chromium.org/b/8846610451251566432
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8846610451251566432
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Ic941925a60538bfd0df2dd77c0cc5a682aa6481d
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/46521
Reviewed-by: 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 653792b..42f0340 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 653792bed324d66be6a77389c80b392230fa08f6
+Subproject commit 42f03409a9ca2d343eef406bf42153d03a662ed2