fix: ci -> purs-tidy version was removed?

Author: srghma

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
         uses: purescript-contrib/setup-purescript@main
         with:
           purescript: "latest"
-          purs-tidy: "latest"
+          purs-tidy: "0.11.1" # "latest"
           spago: "unstable"
 
       - name: Cache PureScript dependencies