add extra src file

Author: skogsbaer

HTF.cabal

@@ -48,6 +48,7 @@ Extra-Source-Files:
   stack-ghc-9.0.yaml
   stack-ghc-9.2.yaml
   stack-ghc-9.4.yaml
+  stack-ghc-9.6.yaml
   tests/bbt/should_fail/BBTArgs
   tests/bbt/should_fail/*.err
   tests/bbt/should_fail/*.out