feat: drop support for PHP < 8.1, symfony < 6.4

Author: Chris8934

tests/Command/GeocodeCommandTest.php

@@ -66,7 +66,12 @@ public function testExecute(): void
             ->willReturn([]);
 
         $app = new Application($kernel);
-        $app->addCommand((new GeocodeCommand($geocoder))->setName('geocoder:geocode'));
+
+        if (method_exists($app, 'addCommand')) {
+            $app->addCommand((new GeocodeCommand($geocoder))->setName('geocoder:geocode'));
+        } else {
+            $app->add((new GeocodeCommand($geocoder))->setName('geocoder:geocode'));
+        }
 
         $command = $app->find('geocoder:geocode');