Make heights match for all inputs for `xs|sm|lg|xl`

[Spiderpig86]

Describe the bug
Input form and button heights should match across xs|sm|lg|xl sizing outside of using form-group.

To Reproduce
Steps to reproduce the behavior:

<form action="#" method="post">
  <div class="u-flex u-gap-1">
    <div class="u-flex-grow-1">
      <input
      type="email"
      name="email"
      id=""
      placeholder="Enter your email"
      class="input--sm"
    />
      <p class="info">We care about your <a href="#" class="u u-LR">privacy.</a></p>
    </div>
    <div class="u-flex-grow-0">
      <button class="text-white bg-indigo-600 border-indigo-600 btn--sm" type="submit">Subscribe</button>
    </div>
  </div>
</form>