🐛(rdfa) fix error on Google Search Console

Google Search Console requires more information for the RDFa information.
Fixed errors:
- Missing field 'hasCourseInstance'
- Either 'courseWorkload' or 'courseSchedule' should be specified (in 'hasCourseInstance')

fixes #2444

src/richie/apps/courses/templates/courses/cms/course_detail.html

@@ -368,22 +368,21 @@ <h2 class="course-detail__title">{% blocktrans context "course_detail__title" %}
             {% block runs %}
                 <div class="course-detail__aside">
                     {% render_model_add course "" "" "get_admin_url_to_add_run" %}
-                    {% with runs_dict=current_page.course.course_runs_dict %}
-                        {% with open_visible_runs=runs_dict.0|add:runs_dict.1|add:runs_dict.2|visible_on_course_page:request.toolbar.edit_mode_active %}
-                            <!--
-                                As course runs are rendered through React, we use meta tags to
-                                setup course runs RFDa properties.
-                             -->
-                            {% for run in open_visible_runs %}
-                                <span rel="hasCourseInstance" typeof="CourseInstance">
-                                    <meta property="name" content="{{ run.title }}"  />
-                                    <meta property="inLanguage" content="{{ run.get_languages_display }}"  />
-                                    <meta property="courseMode" content="online"  />
-                                    <meta property="startDate" content="{{ run.start|date:'Y-m-d' }}"  />
-                                    <meta property="endDate" content="{{ run.end|date:'Y-m-d' }}"  />
-                                </span>
-                            {% endfor %}
-                        {% endwith %}
+                    {% with runs=current_page.course.course_runs|visible_on_course_page:request.toolbar.edit_mode_active %}
+                        <!--
+                            As course runs are rendered through React, we use meta tags to
+                            setup course runs RFDa properties.
+                            -->
+                        {% for run in runs %}
+                            <span rel="hasCourseInstance" typeof="CourseInstance">
+                                <meta property="name" content='{{ run.title|default:current_page.get_title }}' />
+                                <meta property="inLanguage" content="{{ run.get_languages_display }}" />
+                                <meta property="courseMode" content="online" />
+                                <meta property="startDate" content="{{ run.start|date:'Y-m-d' }}"  />
+                                <meta property="endDate" content="{{ run.end|date:'Y-m-d' }}"  />
+                                <meta property="courseWorkload" content="{{ current_page.course.pt_effort }}" />
+                            </span>
+                        {% endfor %}
                     {% endwith %}
                 </div>
             {% endblock runs %}