remove left boarder from upcoming dates

lms/static/sass/features/_course-experience.scss

@@ -509,26 +509,6 @@ button.accordion-trigger, button.prerequisite-button {
       color: theme-color("dark");
       font: -apple-system-body;
     }
-
-    &-todays-date {
-      @include border-left(3px solid $blue);
-    }
-
-    &-verified-upgrade-deadline {
-      @include border-left(3px solid $green);
-    }
-
-    &-verification-deadline-passed {
-      @include border-left(3px solid $red);
-    }
-
-    &-verification-deadline-retry {
-      @include border-left(3px solid $red);
-    }
-
-    &-verification-deadline-upcoming {
-      @include border-left(3px solid $orange);
-    }
   }
 }