BAU Fix failing tests

govuk-frontend v3.1.0 removed the default type attribute on the button
element as it was unnecessary.

alphagov/govuk-frontend#1538

Some of our tests used the type attribute in the selector, so remove
this to get them passing.

test/unit/controllers/payment_reference/get_product_reference_controller_test.js

@@ -53,7 +53,7 @@ describe('product reference index controller', function () {
  expect($('form').attr('action')).to.equal(`/pay/reference/${product.external_id}`)
  expect($('.govuk-label').text()).to.include('Test reference label')
  expect($('#payment-reference-hint').text()).to.include('Test reference hint')
- expect($('button[type=submit]').text()).to.include('Continue')
+ expect($('button').text()).to.include('Continue')
  })
  })
 
@@ -168,7 +168,7 @@ describe('product reference index controller', function () {
  it('should render product reference start page with Welsh text and the Welsh service name', () => {
  expect($('title').text()).to.include(service.service_name.cy)
  expect($('.govuk-header__content').text()).to.include(service.service_name.cy)
- expect($('button[type=submit]').text()).to.include('Parhau')
+ expect($('button').text()).to.include('Parhau')
  })
  })
 
@@ -205,7 +205,7 @@ describe('product reference index controller', function () {
  it('should render product reference start page with Welsh text and the English service name', () => {
  expect($('title').text()).to.include(service.service_name.en)
  expect($('.govuk-header__content').text()).to.include(service.service_name.en)
- expect($('button[type=submit]').text()).to.include('Parhau')
+ expect($('button').text()).to.include('Parhau')
  })
  })
 })