accessibility: make dropdowns accessible (#9475)

#### Motivation

Improve accessibility of dropdowns.

#### Before

Dropdowns are not accessible.

<img width="1219" alt="Screenshot 2025-01-09 at 10 00 36"
src="https://github.com/user-attachments/assets/060198f8-a42f-408c-a39a-b83da55e23c4"
/>

#### Ater

Dropdowns are accessible


![image](https://github.com/user-attachments/assets/e46d6292-913c-458b-acd4-37ed4e1a1e9b)

packages/twenty-front/src/modules/object-record/relation-picker/components/SingleRecordSelectMenuItemsWithSearch.tsx

@@ -92,7 +92,11 @@ export const SingleRecordSelectMenuItemsWithSearch = ({
           <DropdownMenuSeparator />
         </>
       )}
-      <DropdownMenuSearchInput onChange={handleSearchFilterChange} autoFocus />
+      <DropdownMenuSearchInput
+        onChange={handleSearchFilterChange}
+        autoFocus
+        role="combobox"
+      />
       {(dropdownPlacement?.includes('start') ||
         isUndefinedOrNull(dropdownPlacement)) && (
         <>