Disable the check preventing backups of tasks using static chunks

There doesn't seem to be much purpose to this check - chunks are not even used
for backups, and backups of such tasks work fine with the check removed.

Author: SpecLad

changelog.d/20251104_153655_roman_restore_backup_from_share.md

@@ -2,3 +2,9 @@
 
 - Backups of tasks created from a mounted file share no longer fail to import
   (<https://github.com/cvat-ai/cvat/pull/9972>)
+
+### Changed
+
+- It is now possible to back up tasks created from a mounted file share that
+  use static chunk storage
+  (<https://github.com/cvat-ai/cvat/pull/9972>)

cvat/apps/engine/backup.py

@@ -672,10 +672,6 @@ def _export_task(self, zip_obj, target_dir=None):
         self._write_annotation_guide(zip_obj, target_dir)
 
     def export_to(self, file: str | ZipFile, target_dir: str | None = None):
-        if self._db_task.data.storage_method == StorageMethodChoice.FILE_SYSTEM and \
-                self._db_task.data.storage == StorageChoice.SHARE:
-            raise Exception('The task cannot be exported because it does not contain any raw data')
-
         if isinstance(file, str):
             with ZipFile(file, 'w') as zf:
                 self._export_task(zip_obj=zf, target_dir=target_dir)