FIX remove placeholder search text on readonly field

Author: andrewandante

src/Forms/SearchableDropdownTrait.php

@@ -139,7 +139,6 @@ public function getPlaceholder(): string
                 return $emptyString;
             }
         }
-        $name = $this->getName();
         if ($this->getUseDynamicPlaceholder()) {
             if ($this->getIsSearchable()) {
                 if (!$this->getIsLazyLoaded()) {
@@ -598,6 +597,9 @@ public function performReadonlyTransformation()
         $field->setSource($this->sourceList);
         $field->setReadonly(true);
 
+        // Remove the text "Type to search..." on a read-only field
+        $this->setUseDynamicPlaceholder(false);
+
         return $field;
     }
 }