[testcase_gen] Pin paraphrase to tag: 0.1.0 (#1994)

The main branch will support the dart records features, which require
the dart SDK >= 3.0.0, so we pin the `paraphrase` to avoid a break
change.
littleGnAl/paraphrase#1

tool/testcase_gen/pubspec.yaml

@@ -12,7 +12,7 @@ dependencies:
   paraphrase: 
     git:
       url: https://github.com/littleGnAl/paraphrase.git
-      ref: main
+      ref: 0.1.0
 
   args: ^2.3.1