Should I use the verb has or have in the following sentence?
Either verb would be possible.
The verb must agree with the subject none (and not with items, which is the object of the preposition of). Grammar books used to insist that none was always a singular pronoun (like the Old English word for one, from which it was formed). However, most sources today accept the use of none with either a singular or a plural meaning. The choice of verb now depends on the context.
If none refers to a singular or non-count noun (usually found in a prepositional phrase after none), then it is automatically singular in meaning and needs a singular verb:
When none refers to a plural noun, it may take either a singular or a plural verb, depending on the sentence and the intentions of the writer.
If you want to stress that none means not one, use a singular verb:
But when your focus is on the whole group of items or persons, use a plural verb (the usual choice):