fix(setup): runAs root to install tooling

[megglos]

Since camunda/camunda#13418 got merged the zeebe container runs with an unprivileged zeebe user.

As the chaos tooling makes use of apt to install some tools needed to e.g. stress the cpu or modify ip routes we need to also overwrite the runAsUser to root to make that possible still.

Unfortnately the k8s exec API is not offering a way to override the user see https://github.com/kubernetes/kubectl/blob/master/pkg/cmd/exec/exec.go#L104

The first commit resolves an issue that lead to test failure, see testcontainers/testcontainers-go#1359 (comment)

[megglos]

tested manually via chaos-cli

(chaostk) ➜  ./zbchaos disconnect gateway
...
(chaostk) ➜  go-chaos git:(meg-386-root-for-apt) k get deployment zeebe-gateway -o yaml | grep runAs
          runAsUser: 0
          
(chaostk) ➜  ./zbchaos stress broker   
...       
(chaostk) ➜  go-chaos git:(meg-386-root-for-apt) k get statefulset zeebe -o yaml | grep runAs
          runAsUser: 0

[lenaschoenburg]

Thanks for finding a fix 👍