If any index has a non-simple collation, we should fall back to classic, the same way we do for other unsupported index types (partial, sparse, hashed, etc).

Currently we check if the query request has a collation: https://github.com/10gen/mongo/blob/268a45d9962d25a7b9b5b6d995983b575451b31c/src/mongo/db/commands/cqf/cqf_command_utils.cpp#L598

But we don't check for a collation defined on the indexes: https://github.com/10gen/mongo/blob/268a45d9962d25a7b9b5b6d995983b575451b31c/src/mongo/db/commands/cqf/cqf_command_utils.cpp#L611-L614