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/ui/layout/dropdown/components/DropdownMenuItemsContainer.tsx

@@ -51,6 +51,7 @@ export const DropdownMenuItemsContainer = ({
     <StyledDropdownMenuItemsExternalContainer
       hasMaxHeight={hasMaxHeight}
       className={className}
+      role="listbox"
     >
       {hasMaxHeight ? (
         <StyledScrollWrapper
@@ -76,6 +77,7 @@ export const DropdownMenuItemsContainer = ({
       <StyledDropdownMenuItemsExternalContainer
         hasMaxHeight={hasMaxHeight}
         className={className}
+        role="listbox"
       >
         <StyledDropdownMenuItemsInternalContainer>
           {children}