audit: fix check for depending on requirement classes

Don't complain if it's instantiating the class so that it can pass
arguments.

Fixes Homebrew/homebrew#18883.

Library/Homebrew/cmd/audit.rb

@@ -434,7 +434,7 @@ class FormulaAuditor
       problem "`skip_clean :all` is deprecated; brew no longer strips symbols"
     end
 
-    if text =~ /depends_on (.*)\.new\s*[^(]/
+    if text =~ /depends_on (.*)\.new$/
       problem "`depends_on` can take requirement classes directly"
     end
   end