title: Card flex columns doesnt work after add form
body: <p>I add <code>form</code> element into <code>card</code> before <code>card-header</code> in bootstrap 5. After that, the card <code>flex columns</code> doesn't work true and <code>card-footer</code> not show on bottom.</p>
  <p>Before add <code>form</code>:</p>
  <p><a href="https://i.stack.imgur.com/Y3A0q.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Y3A0q.png" alt="enter image description here" /></a></p>
  <p>After add <code>form</code>:</p>
  <p><a href="https://i.stack.imgur.com/aBhqk.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/aBhqk.png" alt="enter image description here" /></a></p>
  <p>How can I fix this problem?</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.side {
    height: 250px;
    background-color: #ddd;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="container"&gt;
    &lt;div class="row"&gt;
      &lt;div class="col-md-4"&gt;
        &lt;div class="side"&gt; &lt;/div&gt;
      &lt;/div&gt;
  
      &lt;div class="col-md-8"&gt;
        &lt;div class="card h-100"&gt;
          &lt;form&gt;
            &lt;div class="card-header"&gt; &lt;/div&gt;
            &lt;div class="card-body"&gt; &lt;/div&gt;
            &lt;div class="card-footer"&gt; &lt;/div&gt;
          &lt;/form&gt;
        &lt;/div&gt;
      &lt;/div&gt;
    &lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>