Incorrect key validation for schemas in `maybe(:array)`

[yauhenininjia]

Describe the bug

Basically it is a reopening of the issue described (and reported as fixed) in #300

Valid keys of nested optional array set via maybe(:array).each(schema) are reported as incorrect. It occurs in latest version 1.13.0 as well

To Reproduce

NestedSchema = Dry::Schema.define do
  required(:bar).filled(:string)
end

BrokenSchema = Dry::Schema.define do
  config.validate_keys = true
  required(:foo).maybe(:array).each(NestedSchema)
end

BrokenSchema.call({ foo: [{ bar: "bar" }] }).errors.to_h

#=> {:foo=>{0=>{:bar=>["is not allowed"]}}}

Expected behavior

errors for the snippet above are empty

My environment

• Affects my production application: NO
• Ruby version: 3.1.0
• OS: macos 11.6.7

[JacobAlexander]

Use Dry::Schema.Params

NestedSchema = Dry::Schema.define do
  required(:bar).filled(:string)
end

BrokenSchema = Dry::Schema.Params do
  required(:foo).maybe(:array).each(NestedSchema)
end

BrokenSchema.call({ foo: [{ bar: 123 }] }).errors.to_h
# => {:foo=>{0=>{:bar=>["must be a string"]}}}

BrokenSchema.call({ foo: [{ bar: '123' }] }).errors.to_h
# => {}