Bugfix/dropdown voice over bug (#2303)

* Remove tabIndex="-1" for Popover component, to fix VoiceOver bug where navigation inside the Popover doesn't work.

This affects Datepicker, Dropdown, Timeline and the Popover components, but appears to cause no bugs.

Ref: https://nav-it.slack.com/archives/C7NE7A8UF/p1694158816166729

* Add changeset

* Might not be the best way, but it works. getFloatingProps added it's own tabIndex="-1", which we need to get rid of.

* Seems like getFloatingProps can take "tabIndex: undefined" as an option, reducing the amount of code we need to change.

.changeset/slimy-rocks-talk.md

@@ -0,0 +1,5 @@
+---
+"@navikt/ds-react": patch
+---
+
+Remove tabIndex="-1" on Popover to fix VoiceOver navigation issue inside Popover

@navikt/core/react/src/popover/Popover.tsx

@@ -210,14 +210,14 @@ export const Popover = forwardRef<HTMLDivElement, PopoverProps>(
         })}
         data-placement={flPlacement}
         aria-hidden={!open || !anchorEl}
-        tabIndex={-1}
         {...getFloatingProps({
           ref: floatingRef,
           style: {
             position: strategy,
             top: y ?? 0,
             left: x ?? 0,
           },
+          tabIndex: undefined,
         })}
         {...rest}
       >