pango: Do not try to add a feature to a caps features ANY

It does not makes sense and asserts

ext/pango/gstbasetextoverlay.c

@@ -1095,7 +1095,10 @@ gst_base_text_overlay_add_feature_and_intersect (GstCaps * caps,
   caps_size = gst_caps_get_size (new_caps);
   for (i = 0; i < caps_size; i++) {
     GstCapsFeatures *features = gst_caps_get_features (new_caps, i);
-    gst_caps_features_add (features, feature);
+
+    if (!gst_caps_features_is_any (features)) {
+      gst_caps_features_add (features, feature);
+    }
   }
 
   gst_caps_append (new_caps, gst_caps_intersect_full (caps,