there's no need to; not necessary to ~
Says that something is unnecessary or not worth doing because it's obvious or easily inferred.
This pattern expresses that an action is unnecessary because the result is already known or can be easily imagined. It's often used when the speaker wants to say 'you don't even need to do X' or 'there's no need to go as far as X'. For example, if the outcome is obvious, you might say 言うまでもない, meaning 'needless to say.' The なく form connects to the next clause, meaning 'without needing to do.' This is a formal, written-style expression that sounds a bit stiff in casual conversation.