bug #648 [AI Bundle] Fix null model names (OskarStark)

This PR was squashed before being merged into the main branch.

Discussion
----------

[AI Bundle] Fix null model names

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| Docs?         | no
| Issues        | Follows #577
| License       | MIT

Commits
-------

b527ecb [AI Bundle] Fix null model names

Author: OskarStark

src/ai-bundle/config/options.php

@@ -190,7 +190,7 @@
                                         ->thenInvalid(\sprintf('The model class "%%s" must extend %s.', Model::class))
                                     ->end()
                                 ->end()
-                                ->stringNode('name')->defaultNull()->end()
+                                ->stringNode('name')->isRequired()->end()
                                 ->arrayNode('options')
                                     ->variablePrototype()->end()
                                 ->end()
@@ -537,7 +537,7 @@
                                         ->thenInvalid(\sprintf('The model class "%%s" must extend %s.', Model::class))
                                     ->end()
                                 ->end()
-                                ->stringNode('name')->defaultNull()->end()
+                                ->stringNode('name')->isRequired()->end()
                                 ->arrayNode('options')
                                     ->variablePrototype()->end()
                                 ->end()

src/ai-bundle/src/AiBundle.php

@@ -514,9 +514,7 @@ private function processAgentConfig(string $name, array $config, ContainerBuilde
         }
 
         $modelDefinition = new Definition($modelClass);
-        if (null !== $modelName) {
-            $modelDefinition->setArgument(0, $modelName);
-        }
+        $modelDefinition->setArgument(0, $modelName);
         if ([] !== $options) {
             $modelDefinition->setArgument(1, $options);
         }
@@ -1125,9 +1123,7 @@ private function processVectorizerConfig(string $name, array $config, ContainerB
         }
 
         $modelDefinition = (new Definition((string) $modelClass));
-        if (null !== $modelName) {
-            $modelDefinition->setArgument(0, $modelName);
-        }
+        $modelDefinition->setArgument(0, $modelName);
         if ([] !== $options) {
             $modelDefinition->setArgument(1, $options);
         }