Update go.mod to force golang.org/x/net to latest

Bumping version and ensuring latest golang.org/x/net as the HTTP rapid reset is triggering primitive vuln scanners, we do not implement a HTTP2 server and are not vulnerable but a minor bump can still help reduce noise for those searching for what they need to upgrade and patch.
diff --git a/go.mod b/go.mod
index 9712d70..ae5a30f 100644
--- a/go.mod
+++ b/go.mod
@@ -13,4 +13,4 @@
 	github.com/gorilla/css v1.0.0 // indirect
 )
 
-retract [v1.0.0, v1.0.24] // Retract older versions as only latest is to be depended upon
+retract [v1.0.0, v1.0.25] // Retract older versions as only latest is to be depended upon