style: Explore Courses button doesn't follow the same style conventions of MFE header (#35994)

lms/templates/header/navbar-authenticated.html

@@ -48,7 +48,7 @@ from openedx.core.djangoapps.site_configuration import helpers as configuration_
       <div class="mobile-nav-item hidden-mobile nav-item nav-tab">
           <a class="tab-nav-link discover-new-link" href="${marketing_link('COURSES')}"
              aria-current="${'page' if '/courses' in request.path else 'false'}">
-             ${_('Discover New')}
+             ${_("Discover New")}
           </a>
       </div>
     % endif

lms/templates/header/navbar-not-authenticated.html

@@ -39,7 +39,7 @@ from openedx.core.djangoapps.user_authn.toggles import should_redirect_to_authn_
   % if allows_login:
     % if can_discover_courses:
       <div class="mobile-nav-item hidden-mobile nav-item">
-        <a href="/courses">${_('Explore courses')}</a>
+        <a href="/courses">${_("Explore courses")}</a>
       </div>
     %endif
   % endif