Only install openssh-client but not openssh-server

This change set solely installs openssh-client instead of openssh which
also installs openssh-server.
The before and after diff of `apk list` looks like the following:

```
diff before.apk-list after.apk-list
33d32
< openssh-9.6_p1-r0 aarch64 {openssh} (SSH-OpenSSH) [installed]
37,39d35
< openssh-server-9.6_p1-r0 aarch64 {openssh} (SSH-OpenSSH) [installed]
< openssh-server-common-9.6_p1-r0 aarch64 {openssh} (SSH-OpenSSH) [installed]
< openssh-sftp-server-9.6_p1-r0 aarch64 {openssh} (SSH-OpenSSH) [installed]
```

The reducation in size is neglectible with 1MB from 208MB to 207MB.

Changelog: removed

Refs #44