custom type not suppot multiple types, raise `Grape::Exceptions::ValidationErrors`

My project use a custom type like this.

module Types
  class Stage
    def self.parse(value)
      "#{value}haha"
    end

    def self.parsed?(value)
      value.is_a? String
    end
  end
end

And defined params like this.

params do
  optional :stage, types: [Array[::Types::Stage], ::Types::Stage]
  optional :province_id, types: [Array[Integer], Integer]
end
get :list do
  p declared(params)
end

There are no problem when I send these requests.

http GET 127.0.0.1:3000/api/list province_id[]==1 # {"stage"=>nil, "province_id"=>[1]}
http GET 127.0.0.1:3000/api/list province_id==1 # {"stage"=>nil, "province_id"=>1}

http GET 127.0.0.1:3000/api/list stage[]==1 # {"stage"=>["1haha"], "province_id"=>nil}

But when I send this request, raise a Grape::Exceptions::ValidationErrors

http GET 127.0.0.1:3000/api/list stage==1
# ~/.rbenv/versions/3.2.2/gemsets/gems/grape-2.0.0/lib/grape/endpoint.rb:363:in `run_validators'
# ~/.rbenv/versions/3.2.2/gemsets/gems/grape-2.0.0/lib/grape/endpoint.rb:258:in `block in run'

I think there is a problem with the call method of lib/grape/validations/types/custom_type_collection_coercer.rb.

def call(value)
  coerced = value.map do |item|
    coerced_item = super(item)

    return coerced_item if coerced_item.is_a?(InvalidValue)

    coerced_item
  end

  @set ? Set.new(coerced) : coerced
end

When use multiple types, there is a possibility that value is not an array.
Maybe should determine unless value.is_a?(Array) and return InvalidValue.new, like DryTypeCoercer#call

If this is correct, I can create a PR to fix it.

Start in lib/grape/validations/types/custom_type_collection_coercer.rb at call and compare its handling with DryTypeCoercer#call. Reproduce the stage==1 request and verify how a non-array value is handled when multiple types are declared. Done means the scalar custom type no longer raises Grape::Exceptions::ValidationErrors while array input continues to work.