Fix small typo in handlers.rst
`do duplicating side-effects` -> `no duplicating side-effects`
@@ -77,7 +77,7 @@ and then ignored.
the operator starts or restarts.
It is the developer's responsibility to make the handlers idempotent
- (re-executable with do duplicating side-effects).
+ (re-executable with no duplicating side-effects).
State-changing handlers
