refactor: PHP 8.5 language features via Rector

rector.php gets the PHP sets up to 8.5. Mostly constructor promotion with
readonly properties, typed class constants, ??=, arrow functions,
str_contains/str_starts_with, catch without unused variables, array_any
and #[\Override] on overridden properties; array_key_exists() keys are
cast to string (null keys are deprecated in PHP 8.5). Long promoted
constructor signatures are wrapped one parameter per line.

Checked locally: a crawl of ~1,900 frontend URLs over all sites and the
backchannel APIs (/api/hotel, /api/product, content feed manifest and
records of every type) render the same as before.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/ep_theme/Configuration/RequestMiddlewares.php

@@ -1,15 +1,19 @@
 <?php
 
+use EP\EpTheme\Middleware\CdnImageMiddleware;
+use EP\EpTheme\Middleware\ReferrerMiddleware;
+use EP\EpTheme\Middleware\HtmxRedirectMiddleware;
+
 return [
     'frontend' => [
         'ep/cdn-images' => [
-            'target' => \EP\EpTheme\Middleware\CdnImageMiddleware::class,
+            'target' => CdnImageMiddleware::class,
             'after' => [
                 'typo3/cms-frontend/page-resolver',
             ],
         ],
         'ep/referrer' => [
-            'target' => \EP\EpTheme\Middleware\ReferrerMiddleware::class,
+            'target' => ReferrerMiddleware::class,
             'after' => [
                 'typo3/cms-frontend/authentication',
             ],
@@ -20,7 +24,7 @@ return [
         // Outermost of the frontend stack after the site is known, so it also sees redirects
         // that core middlewares or exceptions (PropagateResponseException) produce
         'ep/htmx-redirect' => [
-            'target' => \EP\EpTheme\Middleware\HtmxRedirectMiddleware::class,
+            'target' => HtmxRedirectMiddleware::class,
             'after' => [
                 'typo3/cms-frontend/site',
             ],