A user needs to customize the translation for the standard field dependency help text. However, it is not available in the Translation Workbench.
The standard field dependency help text cannot be translated unless the user`s language is changed in the user`s personal settings.
This is working as designed.
There is no way to hide the icon or to customize the translation using the Translation Workbench when the dependency is defined.
Salesforce Help Documentation: N/A