[ObsUX][A11y] Fix focus for popover in details flyout (#218095)

Closes https://github.com/elastic/kibana/issues/212633

## Summary

Fixed navigation by keeping focus on Popover opener element

### How to test
Observability -> Infrastructure -> Infrastructure inventory page.
1. Navigate to any square below All button.
2. Press Enter.
3. Navigate to infographic for Host IP.
4. Press Enter.
5. Press Esc.

Expected result: Navigation continues to next element when Tab key is
pressed.

BEFORE 


https://github.com/user-attachments/assets/e9ee6ff6-895d-408f-b165-0f8edd4eb197

AFTER


https://github.com/user-attachments/assets/b01e6955-b659-4d9a-abcf-1ece48adc161

x-pack/solutions/observability/plugins/infra/public/components/asset_details/tabs/common/popover.tsx

@@ -29,7 +29,7 @@ export const Popover = ({
     <EuiPopover
       panelPaddingSize="s"
       focusTrapProps={{
-        returnFocus: false,
+        returnFocus: true,
       }}
       button={
         <button