mkdocs.yml: Fix validation

Fix `WARNING -  Config value 'validation': Sub-option 'links': Sub-option 'omitted_files': Unrecognised configuration name: omitted_files`

Author: adriendupuis

mkdocs.yml

@@ -5,11 +5,10 @@ repo_url: https://github.com/ibexa/documentation-developer
 site_url: https://doc.ibexa.co/en/latest/
 copyright: "Copyright 1999-2024 Ibexa AS and others"
 validation:
-    links:
-        # omitted_files: warn # TODO: Remove docs/personalization/legacy_recommendation_api.md
-        absolute_links: relative_to_docs
-        unrecognized_links: warn
-        # anchors: warn # TODO: Fix IBX-9578
+    # omitted_files: warn # TODO: Remove docs/personalization/legacy_recommendation_api.md
+    absolute_links: relative_to_docs
+    unrecognized_links: warn
+    # anchors: warn # TODO: Fix IBX-9578
 not_in_nav: |
     search_results.md
     /snippets/*