Error "doas" command not recognised

### What is the issue?

Runned tailscale's install script on debian 12 and it gave some warnings (I don't see this as error, it just needs correction) like "sudo and doas command not found". Sudo is easy as I can simply install sudo or instead run the script without using sudo... But for command "doas" I don't know what to do about it. Can someone help? Thanks!

### Steps to reproduce

Yesterday I tried to install tailscale on CasaOS without success. It just opens a new windows on the browser with CasaOS instead of opening tailscale... "Doesn't matter" I thought to myself, runned tailscale's install script on debian 12 and it gave some warnings (I don't see this as error, it just needs correction) like "sudo and doas command not found". Sudo is easy as I can simply install sudo or instead run the script without using sudo... But for command "doas" I don't know what to do about it.

### Are there any recent changes that introduced the issue?

It seems to me like recent introduced command.

### OS

Linux

### OS version

Debian 12

### Tailscale version

Latest, yesterday.

### Other software

_No response_

### Bug report

_No response_