Merge pull request #12029 from nextcloud/developer/filename-validation

feat(developer): Add note about `IFilenameValidator`

developer_manual/app_publishing_maintenance/app_upgrade_guide/upgrade_to_30.rst

@@ -103,6 +103,7 @@ Added APIs
 - ``OCP\AppFramework\Http\Attribute\OpenAPI::SCOPE_EX_APP`` attribute for scoping APIs only to be used by ExApps.
 - ``OCP\AppFramework\Http\Attribute\ExAppRequired`` attribute for restricting controller methods to be only accessible by ExApps.
 - ``OCP\Collaboration\Reference\IPublicReferenceProvider`` added for reference providers that support reference lookups from public shares.
+- ``OCP\Files\IFilenameValidator`` was added to allow storage independent filename validation.
 
 Changed APIs
 ^^^^^^^^^^^^
@@ -140,5 +141,8 @@ Deprecated APIs
 Removed APIs
 ^^^^^^^^^^^^
 
+- ``OCP\Util::isValidFileName`` was deprecated in 8.1.0 and is now removed, use either ``OCP\Files\Storage\IStorage::verifyPath`` or the new ``OCP\Files\IFilenameValidator``.
+- ``OCP\Util::getForbiddenFileNameChars`` was removed, use either ``OCP\Files\Storage\IStorage::verifyPath`` or the new ``OCP\Files\IFilenameValidator`` for filename validation.
+
 Removed events
 ^^^^^^^^^^^^^^