Enhancement Request: Configure Temp-Doirectory for Cloud-Init ISO

[Zahtu]

Is your feature request related to a problem? Please describe.
Using Vagrant in a WSL - VirtualBox Setup throws errors in provisioning the machine when using the cloud-init feature,
as the host machine (where virtualbox is installed) can not find the compiled cloud-image iso, which is positioned in the local tmp-directory (wsl /tmp/)

Describe the solution you'd like
Having an Option to configure the temporary Directory where the cloud-init iso is compiled to would give anyone the flexibility to set up a path, whicht is usable by the provisioner.
From my point of View, this option should influence https://github.com/hashicorp/vagrant/blob/main/lib/vagrant/action/builtin/cloud_init_setup.rb#L95 Dir.mktmpdir second argument tmpdir can be configured to setup the iso in the requested path.

Additional context
Using vagrant in a WSL-Setup with the provider located on the host-machine results in an error, when using cloud-init action from vagrant: