Fix minor typo in URepeated

`@CountConstraint` doesn't exist in the open source part of Error Prone.

Fixes #2243

FUTURE_COPYBARA_INTEGRATE_REVIEW=#2243 from PicnicSupermarket:rossendrijver/fix_typo ac4bd66
PiperOrigin-RevId: 538593990

core/src/main/java/com/google/errorprone/refaster/URepeated.java

@@ -43,7 +43,7 @@ protected Choice<Unifier> defaultAction(Tree node, @Nullable Unifier unifier) {
   @Override
   public JCExpression inline(Inliner inliner) throws CouldNotResolveImportException {
     throw new UnsupportedOperationException(
-        "@CountConstraint variables should be inlined inside method invocations or newArray");
+        "@Repeated variables should be inlined inside method invocations or newArray");
   }
 
   @Override