Tests: small cleanup

Author: hhugo

compiler/tests-ocaml/lib-effects/dune

@@ -7,12 +7,7 @@
    (:standard -w -38))
   (js_of_ocaml
    (flags
-    (:standard --enable effects))
-   ;; separate compilation doesn't work when using
-   ;; features such as 'effects' or 'use-js-string'
-   ;; because dune doesn't know that it should compile
-   ;; multiple versions of the dependencies
-   (compilation_mode whole_program))))
+    (:standard --enable effects)))))
 
 (executables
  (enabled_if