chore: fix arrow position in Firefox

components/popover/style/index.less

@@ -111,7 +111,7 @@
   &-placement-top > &-content > &-arrow,
   &-placement-topLeft > &-content >  &-arrow,
   &-placement-topRight > &-content >  &-arrow {
-    bottom: @popover-distance - @popover-arrow-width + 1px;
+    bottom: @popover-distance - @popover-arrow-width + 1.5px;
     box-shadow: 3px 3px 7px rgba(0, 0, 0, 0.07);
   }
   &-placement-top > &-content >  &-arrow {