revert upgrade for now

Author: cpanato

go.mod

@@ -6,7 +6,7 @@ toolchain go1.24.3
 
 require (
 	cloud.google.com/go/storage v1.55.0
-	github.com/GoogleCloudPlatform/testgrid v0.0.174
+	github.com/GoogleCloudPlatform/testgrid v0.0.38
 	github.com/blang/semver/v4 v4.0.0
 	github.com/cheggaaa/pb/v3 v3.1.7
 	github.com/go-git/go-git/v5 v5.16.0
@@ -50,7 +50,6 @@ require (
 )
 
 require (
-	bitbucket.org/creachadair/stringset v0.0.14 // indirect
 	cel.dev/expr v0.24.0 // indirect
 	cloud.google.com/go v0.121.2 // indirect
 	cloud.google.com/go/auth v0.16.1 // indirect