fix(ui): add missing aria-label to SearchField components

Add aria-label attributes to SearchField components to fix
accessibility warnings from React Aria.

- Select: add aria-label to SearchField using searchPlaceholder
- MenuAutocomplete: add aria-label to RASearchField, remove
  redundant aria-label from RAInput
- MenuAutocompleteListbox: same as MenuAutocomplete

Per React Aria docs, aria-label should be on SearchField, not
the child Input.

Signed-off-by: Johan Persson <johanopersson@gmail.com>

.changeset/bumpy-carrots-stare.md

@@ -0,0 +1,7 @@
+---
+'@backstage/ui': patch
+---
+
+Added missing `aria-label` attributes to `SearchField` components in `Select`, `MenuAutocomplete`, and `MenuAutocompleteListbox` to fix accessibility warnings.
+
+Affected components: Select, MenuAutocomplete, MenuAutocompleteListbox

packages/ui/src/components/Menu/Menu.tsx

@@ -255,13 +255,13 @@ export const MenuAutocomplete = (props: MenuAutocompleteProps<object>) => {
               classNames.searchField,
               styles[classNames.searchField],
             )}
+            aria-label={props.placeholder || 'Search'}
           >
             <RAInput
               className={clsx(
                 classNames.searchFieldInput,
                 styles[classNames.searchFieldInput],
               )}
-              aria-label="Search"
               placeholder={props.placeholder || 'Search...'}
             />
             <RAButton
@@ -334,13 +334,13 @@ export const MenuAutocompleteListbox = (
             classNames.searchField,
             styles[classNames.searchField],
           )}
+          aria-label={props.placeholder || 'Search'}
         >
           <RAInput
             className={clsx(
               classNames.searchFieldInput,
               styles[classNames.searchFieldInput],
             )}
-            aria-label="Search"
             placeholder={props.placeholder || 'Search...'}
           />
           <RAButton

packages/ui/src/components/Select/SelectContent.tsx

@@ -55,6 +55,7 @@ export function SelectContent({
           classNames.searchWrapper,
           styles[classNames.searchWrapper],
         )}
+        aria-label={searchPlaceholder}
       >
         <Input
           placeholder={searchPlaceholder}