fix: catch ruby3.3 format NoMethodError message (#1579)

ruby3.3.0dev changes the error messages on NoMethodError with the following
commit / issue:

ruby/ruby#6950
https://bugs.ruby-lang.org/issues/18285

So to catch this new NoMethodError message, modify regex accordingly.

Fixes #1578 .

lib/shoulda/matchers/independent/delegate_method_matcher.rb

@@ -400,7 +400,7 @@ def subject_handles_nil_delegate_object?
                 false
               rescue NoMethodError => e
                 if e.message =~
-                   /undefined method `#{delegate_method}' for nil:NilClass/
+                   /undefined method `#{delegate_method}' for nil/
                   false
                 else
                   raise e