Problem installing vagrant-serverspec plugin

I have Ubuntu 24.04 and have installed vagrant 2.2.19. When trying to install the vagrant-serverspec plugin it complains of the installed Ruby version:

$ vagrant plugin install vagrant-serverspec
Installing the 'vagrant-serverspec' plugin. This can take a few minutes...
Vagrant failed to properly resolve required dependencies. These
errors can commonly be caused by misconfigured plugin installations
or transient network issues. The reported error is:

rspec-its requires Ruby version > 3.0.0. The current ruby version is 2.7.4.191.

The thing is that I do have a qualifying ruby version installed:

$ ruby --version
ruby 3.2.3 (2024-01-18 revision 52bb2ac0a6) [x86_64-linux-gnu]

I don’t know where it is getting that ruby 2.7.4.191 is installed. Any ideas on how to solve this?