chore: make dropdown not editable (#2280)

Author: LynxLynxx

catalyst_voices/apps/voices/lib/widgets/dropdown/voices_dropdown.dart

@@ -88,6 +88,7 @@ class SingleSelectDropdown<T> extends VoicesFormField<T> {
             return ConstrainedBox(
               constraints: const BoxConstraints(),
               child: DropdownMenu(
+                requestFocusOnTap: false,
                 controller: state._controller,
                 focusNode: focusNode,
                 expandedInsets: EdgeInsets.zero,
@@ -112,7 +113,6 @@ class SingleSelectDropdown<T> extends VoicesFormField<T> {
                   ),
                   focusColor: Colors.tealAccent,
                 ),
-
                 errorText: field.errorText,
                 // using visibility so that the widget reserves
                 // the space for the icon, otherwise when widget changes