try installing Shizuku and app-ops from play store
and activate Shizuku using PC or root and activate app-ops via Shizuku
then in app-ops navigate to WhatsApp and after pressing it go to contacts permission and choose to ignore it
this will trick WhatsApp that you have given it contacts permission but with null data

**OR**

you can just do it via ADB or rooted terminal in your phone using `adb shell` to access your phone interactive shell and seeing the `$` sign
then write this code

    appops set com.whatsapp CONTACTS ignore
to ignore contacts permission in WhatsApp where `com.whatsapp` is the WhatsApp package name