fix: respect PATH env variable for runitdir in alpine #152

[q0rban]

An alternate solution to #152

Resolves #152

Testing instructions:

• task -- alpine
• Then run each tag created to see if they are healthy:

$ image=tugboatqa/alpine:3.20.3

$ container=$(docker run --detach --rm $image)

$ docker ps --filter "id=$container" --format "{{ .State }}"
running

$ docker rm -f $container

[rabbitlair]

Code changes make sense, and all tags worked like a charm during my tests. Thank you!

[jcbain]

Late to the review but I like it!