roll: gn

From: git_revision:2c801de70b8ed3c8e404245d61d32a3d61b328d0
To: git_revision:b175fa5d6ae1640742aad593185780a08f6ba224

CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I8a59af22fb80f8ed020fa0134f2fb8e9281a2e0f
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 719a59e..abe217c 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
@@ -2,7 +2,7 @@
   {
     "path": "gn/gn/${os}-${arch=amd64}",
     "tags": [
-      "git_revision:2c801de70b8ed3c8e404245d61d32a3d61b328d0"
+      "git_revision:b175fa5d6ae1640742aad593185780a08f6ba224"
     ]
   },
   {