fix: items allows the presence of boolean schemas

[macisamuele]

While working on https://github.com/macisamuele/jsonschema-equivalent I've noticed that having boolean schemas into items keyword result into an invalid schema, when instead it should be considered valid.

Example:

{
    "additionalItems": false,
    "items": true
}

is considered an invalid schema but according to the draft (section 6.4.1)

The value of "items" MUST be either a valid JSON Schema or an array of valid JSON Schemas.

and true or false are valid JSON Schemas.

The goal of this PR is to fix this.

PS: I'm aware that the example schema is unlikely to be composed by humans as it really is as restrictive as true schema, but it is still a possible valid schema.

[Stranger6667]

Hi @macisamuele !

Thanks! Will release a new version today :)

[Stranger6667]

Can you, please, add a changelog entry?

[macisamuele]

Will release a new version today :)

Sure thing, in the mean time I'm trying to add more test coverage on the other project, so I can easily work with a patched crates.io ;)

Can you, please, add a changelog entry?

Doing it right now