Fix Python 3.10 collections import

src/backend/utils.py

@@ -4,7 +4,6 @@
 """Various utilities that are used throughout the package."""
 
 import asyncio
-import collections
 import html
 import inspect
 import io
@@ -43,6 +42,11 @@ else:
     from async_generator import asynccontextmanager
     current_task = asyncio.Task.current_task
 
+if sys.version_info >= (3, 10):
+    import collections.abc as collections
+else:
+    import collections
+
 Size       = Tuple[int, int]
 BytesOrPIL = Union[bytes, PILImage.Image]
 auto       = autostr