Fieldset causing content to be cut-off

**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
4. 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](https://github.com/canonical/ubuntu.com/pull/12659) filed that addresses this problem by setting all fieldset elements to have `overflow: visible`

Reproduce the problem at ubuntu.com/openstack/contact-us by opening the phone-number country-code dropdown. Then find the framework rule applying overflow:auto to fieldset and verify the fix against the expected overlapping dropdown; the issue links a related ubuntu.com pull request for context.

Written by the indexing model from the issue text.