style(Popover): improve cursor (#7623)

src/popover/index.less

@@ -34,6 +34,7 @@
     padding: 0 @padding-md;
     font-size: @popover-action-font-size;
     line-height: @line-height-md;
+    cursor: pointer;
 
     &:last-child {
       .van-popover__action-text::after {
@@ -212,6 +213,7 @@
 
       &--disabled {
         color: @popover-light-action-disabled-text-color;
+        cursor: not-allowed;
 
         &:active {
           background-color: transparent;