Do not generate warnings for the presence tests in a validator module

[matiwinnetou]

What Git revision are you using?

main one as of time of writing

What operating system are you using, and which version?

• [x ] macOS

Describe what the problem is?

I added one test to my code and got the following warning:

  ⚠ While trying to make sense of your code...
  ╰─▶ I found a public definition in a validator module.
      Definitions in validator modules do not need to be public.
      
     ╭─[/Users/mati/Devel/OpenSource/aiken/examples/english_auction/validators/english_auction.ak:345:1]
 345 │ 
 346 │ test get_payment_addr_hash_test() {
     · ───
 347 │   let bytes = #[1]
     ╰────

Summary
    0 errors, 1 warning

What should be the expected behavior?

I didn't expect any warnings.