catch exception on delete assets
Fix for obsolete cache, FileNotFound error is shown when a datasets does not have either assets or cached assets:
```
ERROR: 2023-11-07 15:42:28,461 - root - Unexpected error.
Traceback (most recent call last):
File "/src/services/admin/src/admin/routes/obsolete_cache.py", line 126, in delete_obsolete_cache_endpoint
delete_obsolete_cache(
File "/src/services/admin/src/admin/routes/obsolete_cache.py", line 95, in delete_obsolete_cache
cached_assets_storage_client.delete_dataset_directory(dataset)
File "/src/libs/libcommon/src/libcommon/storage_client.py", line 50, in delete_dataset_directory
self._fs.rm(dataset_key, recursive=True)
File "/src/services/admin/.venv/lib/python3.9/site-packages/fsspec/asyn.py", line 118, in wrapper
return sync(self.loop, func, *args, **kwargs)
File "/src/services/admin/.venv/lib/python3.9/site-packages/fsspec/asyn.py", line 103, in sync
raise return_result
File "/src/services/admin/.venv/lib/python3.9/site-packages/fsspec/asyn.py", line 56, in _runner
result[0] = await coro
File "/src/services/admin/.venv/lib/python3.9/site-packages/s3fs/core.py", line 1920, in _rm
paths = await self._expand_path(path, recursive=recursive)
File "/src/services/admin/.venv/lib/python3.9/site-packages/fsspec/asyn.py", line 864, in _expand_path
out = await self._expand_path([path], recursive, maxdepth)
File "/src/services/admin/.venv/lib/python3.9/site-packages/fsspec/asyn.py", line 893, in _expand_path
raise FileNotFoundError(path)
FileNotFoundError: ['hf-datasets-server-statics/cached-assets/typeof/acapla']

```
Will also fix https://github.com/huggingface/datasets-server/issues/2057
catch exception on delete assets: Fix for obsolete cache, FileNotFound error is shown when a datasets does not have either assets or cached assets:
```
ERROR: 2023-11-07 15:42:28,461 - root - Unexpected error.
Traceback (most recent call last):
File "/src/services/admin/src/admin/routes/obsolete_cache.py", line 126, in delete_obsolete_cache_endpoint
delete_obsolete_cache(
File "/src/services/admin/src/admin/routes/obsolete_cache.py", line 95, in delete_obsolete_cache
cached_assets_storage_client.delete_dataset_directory(dataset)
File "/src/libs/libcommon/src/libcommon/storage_client.py", line 50, in delete_dataset_directory
self._fs.rm(dataset_key, recursive=True)
File "/src/services/admin/.venv/lib/python3.9/site-packages/fsspec/asyn.py", line 118, in wrapper
return sync(self.loop, func, *args, **kwargs)
File "/src/services/admin/.venv/lib/python3.9/site-packages/fsspec/asyn.py", line 103, in sync
raise return_result
File "/src/services/admin/.venv/lib/python3.9/site-packages/fsspec/asyn.py", line 56, in _runner
result[0] = await coro
File "/src/services/admin/.venv/lib/python3.9/site-packages/s3fs/core.py", line 1920, in _rm
paths = await self._expand_path(path, recursive=recursive)
File "/src/services/admin/.venv/lib/python3.9/site-packages/fsspec/asyn.py", line 864, in _expand_path
out = await self._expand_path([path], recursive, maxdepth)
File "/src/services/admin/.venv/lib/python3.9/site-packages/fsspec/asyn.py", line 893, in _expand_path
raise FileNotFoundError(path)
FileNotFoundError: ['hf-datasets-server-statics/cached-assets/typeof/acapla']

```
Will also fix https://github.com/huggingface/datasets-server/issues/2057