Record your message using your phone’s built-in recorder app (like Voice Memos on iPhone or Voice Recorder on Android). Use the app's native trim or edit tools to cut the audio, then share that file to WhatsApp.
In 2022, WhatsApp widely rolled out the ability to your voice notes before sending them. While you can't "cut" a segment out of the middle, this allows you to stop and restart if you make a mistake. How to use: 2022---WhatsApp--How-to-cut-voice-messages
How to to your phone's storage for editing. Record your message using your phone’s built-in recorder