page_limit config must accept null

Author: garak

src/DependencyInjection/Configuration.php

@@ -49,8 +49,16 @@ public function getConfigTreeBuilder(): TreeBuilder
                 ->scalarNode('page_range')
                 ->defaultValue(5)
                 ->end()
-                ->integerNode('page_limit')
+                ->scalarNode('page_limit')
                 ->defaultNull()
+                ->validate()
+                    ->ifTrue(static fn (mixed $v): bool => null !== $v && !\is_int($v))
+                    ->thenInvalid('The page_limit must be an integer or null.')
+                ->end()
+                ->beforeNormalization()
+                ->ifNull()
+                ->then(static fn (mixed $v): int => 5)
+                ->end()
                 ->end()
                 ->booleanNode('convert_exception')
                 ->defaultFalse()