Replace UK phone numbers in tests with US numbers

app/main/forms.py

@@ -14,7 +14,6 @@ from notifications_utils.formatters import strip_all_whitespace
 from notifications_utils.insensitive_dict import InsensitiveDict
 from notifications_utils.recipients import (
     InvalidPhoneError,
-    normalise_phone_number,
     validate_phone_number,
 )
 from werkzeug.utils import cached_property
@@ -1538,10 +1537,9 @@ class ServiceContactDetailsForm(StripWhitespaceForm):
             self.email_address.validators = [DataRequired(), Length(min=5, max=255), ValidEmail()]
 
         elif self.contact_details_type.data == 'phone_number':
-            # we can't use the existing phone number validation functions here since we want to allow landlines
             def valid_phone_number(self, num):
                 try:
-                    normalise_phone_number(num.data)
+                    validate_phone_number(num.data, international=True)
                     return True
                 except InvalidPhoneError:
                     raise ValidationError('Must be a valid phone number')