Allow deletion race conditions to work with purge

discord/abc.py

@@ -49,7 +49,7 @@
 from .object import OLDEST_OBJECT, Object
 from .context_managers import Typing
 from .enums import ChannelType, InviteTarget
-from .errors import ClientException
+from .errors import ClientException, NotFound
 from .mentions import AllowedMentions
 from .permissions import PermissionOverwrite, Permissions
 from .role import Role
@@ -122,7 +122,14 @@ def __repr__(self) -> str:
 
 async def _single_delete_strategy(messages: Iterable[Message], *, reason: Optional[str] = None):
     for m in messages:
-        await m.delete()
+        try:
+            await m.delete()
+        except NotFound as exc:
+            if exc.code == 10008:
+                continue  # bulk deletion ignores not found messages, single deletion does not.
+            # several other race conditions with deletion should fail without continuing,
+            # such as the channel being deleted and not found.
+            raise
 
 
 async def _purge_helper(