[UPMERGE] 1.1 -> 1.2 (#162)

This PR has been generated automatically.

**Remember!** The upmerge should always be merged using the `Merge pull
request` button.

In case of conflicts, resolve them manually:
```bash
git fetch upstream
gh pr checkout <this-pr-number>
git merge upstream/1.2 -m "Resolve conflicts between 1.1 and 1.2"
git push
```

Author: TheMilek

src/Form/Type/PageType.php

@@ -61,6 +61,7 @@ public function buildForm(FormBuilderInterface $builder, array $options): void
                 'label' => 'sylius_cms.ui.collections',
                 'multiple' => true,
                 'by_reference' => false,
+                'required' => false,
             ])
             ->add('channels', ChannelChoiceType::class, [
                 'label' => 'sylius_cms.ui.channels',