Revert error handling (stale events are better than nothing)

This is done so empty calendars are not produced on errors (effectively
removing all events from the user's calendar). Calendar apps tend to
leave old events in place if they fail to update them (non-200 response)
and it seems like it's better to have stale events rather than nothing
while the error is being fixed.

src/main_api.py

@@ -6,8 +6,6 @@
 
 from aiohttp import ClientSession
 
-from utils.error_handling import catch_errors_to_empty_iter
-
 logger = logging.getLogger(__name__)
 
 _API_BASE_URL = "https://my.itmo.ru/api"
@@ -34,14 +32,12 @@ async def _get_calendar(session: ClientSession, auth_token: str, path: str) -> d
     return await resp.json()
 
 
-@catch_errors_to_empty_iter
 async def get_raw_lessons(session: ClientSession, auth_token: str) -> Iterable[dict]:
     resp_json = await _get_calendar(session, auth_token, "/schedule/schedule/personal")
     days = resp_json["data"]
     return (dict(date=day["date"], **lesson) for day in days for lesson in day["lessons"])
 
 
-@catch_errors_to_empty_iter
 async def get_raw_pe_lessons(session: ClientSession, auth_token: str) -> Iterable[dict]:
     resp_json = await _get_calendar(session, auth_token, "/sport/my_sport/calendar")
     days = resp_json["result"]