chore: upgrade phpunit to 12.5

tests/Saas/ApiClientTest.php

@@ -14,9 +14,8 @@ class ApiClientTest extends TestCase
     /**
      * The whole point of the calendar-month argument: the app never has to know that the
      * API counts from zero.
-     *
-     * @dataProvider provideMonths
      */
+    #[\PHPUnit\Framework\Attributes\DataProvider('provideMonths')]
     public function testItTranslatesTheCalendarMonthIntoTheApiIndex(int $month, string $expectedPath): void
     {
         $requested = null;