fix(task): css border improvements

Author: hawkeye64

ui/src/css/calendar-task.sass

@@ -259,6 +259,9 @@
     &--day
       border-right: var(--calendar-border)
 
+      &:last-child
+        border-right: none
+
   &__footer
     font-weight: var(--calendar-head-font-weight)
 
@@ -273,6 +276,9 @@
       background: var(--calendar-background)
       border-right: var(--calendar-border)
 
+      &:last-child
+        border-right: none
+
 .q-dark div,
 .body--dark div,
 .q-calendar--dark