Skylark: Remove static type checks

--
MOS_MIGRATED_REVID=91175430
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/ConditionalExpression.java b/src/main/java/com/google/devtools/build/lib/syntax/ConditionalExpression.java
index 46471b3..1c43bae 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/ConditionalExpression.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/ConditionalExpression.java
@@ -62,9 +62,9 @@
   }
 
   @Override
-  SkylarkType validate(ValidationEnvironment env) throws EvalException {
+  void validate(ValidationEnvironment env) throws EvalException {
     condition.validate(env);
-    return thenCase.validate(env)
-        .infer(elseCase.validate(env), "else case", thenCase.getLocation(), elseCase.getLocation());
+    thenCase.validate(env);
+    elseCase.validate(env);
   }
 }