Fix Collection::implode() string argument (#41468)

collect(['foo', 'bar'])->implode('_') should be 'foo-bar' but it
instead attempts to call translator helper _().

For callable only support Closure, an invokable class, or a
[class, 'method'] array pair.

Collection.php

@@ -583,7 +583,7 @@ public function hasAny($key)
      */
     public function implode($value, $glue = null)
     {
-        if (is_callable($value)) {
+        if ($this->useAsCallable($value)) {
             return implode($glue ?? '', $this->map($value)->all());
         }