ActionList: Prevent scroll when an item is selected with Space (#4259)

* prevent default on Space

* immediately reset defaultPrevented

* improve comment

* Create slow-owls-report.md

Author: siddharthkp

.changeset/slow-owls-report.md

@@ -0,0 +1,5 @@
+---
+"@primer/react": patch
+---
+
+ActionList: Prevent scroll when an item is selected with `Space`

packages/react/src/ActionList/Item.tsx

@@ -229,6 +229,12 @@ export const Item = React.forwardRef<HTMLLIElement, ActionListItemProps>(
       (event: React.KeyboardEvent<HTMLLIElement>) => {
         if (disabled || inactive) return
         if ([' ', 'Enter'].includes(event.key)) {
+          if (event.key === ' ') {
+            event.preventDefault() // prevent scrolling on Space
+            // immediately reset defaultPrevented once it's job is done
+            // so as to not disturb the functions that use that event after this
+            event.defaultPrevented = false
+          }
           onSelect(event, afterSelect)
         }
       },