Fieldset causing content to be cut-off

[petesfrench]

Describe the bug

the fieldset element has overflow: auto, this can cause some content to be cut-off and requires scrolling to reach that content. This is most apparent with the phone number dropdown found on all forms (see screenshot below)

To Reproduce

Steps to reproduce the behavior:

1. Go to https://ubuntu.com/openstack/contact-us
2. Click on the phone number country code drop down
3. See it is cut off by the fieldset and a scroll option appears to reveal the full content

Expected behavior

The country code drop to overlap the field set

Screenshots

Additional context

I have this issue filed that addresses this problem by setting all fieldset elements to have overflow: visible