fix: Add T as a possible return type for lastOr and firstOr

Author: Bl00D4NGEL

src/Domain/Collection.php

@@ -163,7 +163,7 @@ public function first(callable $callback = null)
      * @template U of T|mixed
      * @param ?callable(T, int, static): bool $callback
      * @param U $fallbackValue
-     * @return U
+     * @return U|T
      * @throws InvalidArgumentException
      */
     public function firstOr(callable $callback = null, mixed $fallbackValue = null)
@@ -213,7 +213,7 @@ public function last(callable $callback = null)
      * @template U of T|mixed
      * @param ?callable(T, int, static): bool $callback
      * @param U $fallbackValue
-     * @return U
+     * @return U|T
      * @throws InvalidArgumentException
      */
     public function lastOr(callable $callback = null, mixed $fallbackValue = null)