update goctl version to 1.2.1 (#1042)

tools/goctl/internal/version/version.go

@@ -6,7 +6,7 @@ import (
 )
 
 // BuildVersion is the version of goctl.
-const BuildVersion = "1.2.0"
+const BuildVersion = "1.2.1"
 
 // GetGoctlVersion returns BuildVersion
 func GetGoctlVersion() string {