[Feature] update footer to reflect upstream vocab changes

[Queen-codes]

Problem

The current footer is outdated in a way, as it doesn't reflect the changes made upstream in vocabulary following the merge of this pr

• [Fix] Includes validation for newsletter form vocabulary#180

Description

The footer section in the Vocabulary codebase has been updated to remove the empty string in the required attribute for the form input and also the removal of novalidate, and the footer in the search portal needs to be modified to reflect its change.

Implementation

• I would be interested in implementing this feature.