Remove outdated reference to Ant

tools/cldr/cldr-to-icu/src/main/java/org/unicode/icu/tool/cldrtoicu/ant/CleanOutputDirectoryTask.java

@@ -88,8 +88,8 @@ public CleanOutputDirectoryTask() {
     public static final class Retain extends Task {
         private Path path = null;
 
-        // Don't use "Path" for the argument type because that always makes an absolute path (e.g.
-        // relative to the working directory for the Ant task). We want relative paths.
+        // Don't use "Path" for the argument type because that always makes an absolute path
+        // (e.g. relative to the working directory). We want relative paths.
         public void setPath(String path) {
             Path p = Paths.get(path).normalize();
             checkBuild(!p.isAbsolute() && !p.startsWith(".."), "invalid path: %s", path);