Add class to section title on Password Assistance page (#25812)

lms/templates/student_account/login.underscore

@@ -24,7 +24,7 @@
     </p>
     <p><%- gettext("To continue learning with this account, sign in below.") %></p>
 <% } else { %>
-    <h1><%- gettext("Sign In") %></h1>
+    <h1 class="section-title"><%- gettext("Sign In") %></h1>
 <% } %>
 
 <form id="login" class="login-form" tabindex="-1" method="POST">

lms/templates/student_account/password_reset.underscore

@@ -1,7 +1,7 @@
 <div class="js-form-feedback" aria-live="assertive" tabindex="-1">
 </div>
 
-<h1><%- gettext("Password assistance") %></h1>
+<h1 class="section-title"><%- gettext("Password assistance") %></h1>
 
 <form id="password-reset" class="password-reset-form" tabindex="-1" method="POST">