Issue #3459321: [DSFR 1.11] Swap the tag of the conset banner

Closes #3459321

templates/patterns/consent_banner/pattern-consent-banner.html.twig

 {% set modal_id = 'fr-consent-modal' %}
 
 <div{{ attributes.addClass('fr-consent-banner') }}>
-  {% if title %}<p class="fr-h6 fr-mb-3v">{{ title }}</p>{% endif %}
+  {% if title %}<h4 class="fr-h6 fr-mb-3v">{{ title }}</h4>{% endif %}
   <div class="fr-consent-banner__content">
     <p class="fr-text--sm">{{ content }}</p>
   </div>