Replacing the tape, as per @andy256, should do the trick. But if acquiring new tape were not an option, you could add one or more extra layers to the tape rim, in order to soften the concavities in each spoke hole visible in your picture. There are several alternatives here. This one seems particularly appealing.

Replacing the tape, as per @andy256, should do the trick. But if acquiring new tape were not an option, you could add one or more extra layers on top of the old rim tape, in order to soften the concavities in each spoke hole visible in your picture. There are several alternatives here. This one seems particularly appealing.