feat: proconnect button link

Author: hugues-m

apps/web/src/app/(public)/(authentication)/connexion/ProConnectSigninButton.tsx

@@ -43,8 +43,8 @@ const ProConnectSigninButton = ({
       </Button>
 
       <a
-        className="fr-link fr-link--sm wip-outline"
-        href="/"
+        className="fr-link fr-link--sm"
+        href="https://www.proconnect.gouv.fr/"
         target="_blank"
         rel="noreferrer"
       >