main/doas: change PATH for consistency with Alpine's default
Use the same PATH as in openssh, sudo and /etc/profile.
We are currently working on getting Alpine Linux 3.21 out. This means that merge requests that are not aimed to help with that (only affecting testing, new aports) have a lower priority at the moment. Please be patient, they will be eventually picked up.
Use the same PATH as in openssh, sudo and /etc/profile.