Remove unused in_explorer parameter in StatusSidePanel

It's never used directly in the template. The value that is used in the
side_panels.html template does not come from this parameter, because
that is a wrapper template and not the status panel itself. Instead, the
value is passed when the template is included, i.e. {% include ...
in_explorer=True %}.

wagtail/admin/ui/side_panels.py

@@ -68,18 +68,14 @@ class BaseStatusSidePanel(BaseSidePanel):
         show_schedule_publishing_toggle=None,
         live_object=None,
         scheduled_object=None,
-        in_explorer=False,
         locale=None,
         translations=None,
         **kwargs,
     ):
         super().__init__(*args, **kwargs)
-        self.show_schedule_publishing_toggle = (
-            show_schedule_publishing_toggle and not in_explorer
-        )
+        self.show_schedule_publishing_toggle = show_schedule_publishing_toggle
         self.live_object = live_object
         self.scheduled_object = scheduled_object
-        self.in_explorer = in_explorer
         self.locale = locale
         self.translations = translations
         self.locking_enabled = isinstance(self.object, LockableMixin)
@@ -254,7 +250,6 @@ class PageStatusSidePanel(BaseStatusSidePanel):
         if page.id:
             context.update(
                 {
-                    "in_explorer": self.in_explorer,
                     "live_object": self.live_object,
                     "scheduled_object": self.scheduled_object,
                     "history_url": reverse(

wagtail/admin/views/pages/create.py

@@ -348,7 +348,6 @@ class CreateView(TemplateResponseMixin, ContextMixin, HookResponseMixin, View):
                 self.page,
                 self.request,
                 show_schedule_publishing_toggle=self.form.show_schedule_publishing_toggle,
-                in_explorer=False,
                 locale=self.locale,
                 translations=self.translations,
             ),

wagtail/admin/views/pages/edit.py

@@ -864,7 +864,6 @@ class EditView(TemplateResponseMixin, ContextMixin, HookResponseMixin, View):
                 show_schedule_publishing_toggle=self.form.show_schedule_publishing_toggle,
                 live_object=self.real_page_record,
                 scheduled_object=self.scheduled_page,
-                in_explorer=False,
                 locale=self.locale,
                 translations=self.translations,
             ),

wagtail/admin/views/pages/listing.py

@@ -200,7 +200,6 @@ class IndexView(PermissionCheckedMixin, BaseListingView):
                 show_schedule_publishing_toggle=False,
                 live_object=self.parent_page,
                 scheduled_object=self.scheduled_page,
-                in_explorer=True,
                 locale=self.locale,
                 translations=self.translations,
             ),

wagtail/admin/views/pages/revisions.py

@@ -86,7 +86,6 @@ def revisions_revert(request, page_id, revision_id):
             show_schedule_publishing_toggle=form.show_schedule_publishing_toggle,
             live_object=page,
             scheduled_object=scheduled_page,
-            in_explorer=False,
             locale=locale,
             translations=translations,
         ),