roll: buildifier

From: version:2@4.0.1
To: version:2@4.2.1

CQ-Do-Not-Cancel-Tryjobs: true
Roller-URL: https://ci.chromium.org/b/8836261165565982945
Cq-Cl-Tag: roller-builder:buildifier-roller
Cq-Cl-Tag: roller-bid:8836261165565982945
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Ibc093f8365b640ed517d9e21c38bc46e88815e3a
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/60640
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed.google.com.iam.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/pw_env_setup/py/pw_env_setup/cipd_setup/pigweed.json b/pw_env_setup/py/pw_env_setup/cipd_setup/pigweed.json
index aa4c750..78005f6 100644
--- a/pw_env_setup/py/pw_env_setup/cipd_setup/pigweed.json
+++ b/pw_env_setup/py/pw_env_setup/cipd_setup/pigweed.json
@@ -207,7 +207,7 @@
       "windows-amd64"
     ],
     "tags": [
-      "version:2@4.0.1"
+      "version:2@4.2.1"
     ]
   }
 ]