Fix typo in manual's description of isdone (#44306)

Closes #44283

doc/src/manual/interfaces.md

@@ -17,7 +17,7 @@ to generically build upon those behaviors.
 | `eltype(IterType)` | `Any` | The type of the first entry of the tuple returned by `iterate()` |
 | `length(iter)` | (*undefined*) | The number of items, if known |
 | `size(iter, [dim])` | (*undefined*) | The number of items in each dimension, if known |
-| `Base.isdone(iter[, state])` | `missing` | Fast-path hint for iterator completion. Should be defined for mutable iterators, or else `isempty(iter)` will call `iterate(iter[, state])` and may mutate the iterator. |
+| `Base.isdone(iter[, state])` | `missing` | Fast-path hint for iterator completion. Should be defined for stateful iterators, or else `isempty(iter)` may call `iterate(iter[, state])` and mutate the iterator. |
 
 | Value returned by `IteratorSize(IterType)` | Required Methods |
 |:------------------------------------------ |:------------------------------------------ |