alpine: sshd: enable PAM

So as to load `/etc/environment` via `pam_env`.

This has been already applied to alpine-lima ISO via `genapkovl-lima.sh`.
https://github.com/lima-vm/alpine-lima/blob/v0.2.39/genapkovl-lima.sh#L95

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

Author: AkihiroSuda

pkg/cidata/cidata.TEMPLATE.d/boot/10-alpine-prep.sh

@@ -29,6 +29,8 @@ usermod -p '*' "${LIMA_CIDATA_USER}"
 
 # Alpine disables TCP forwarding, which is needed by the lima-guestagent
 sed -i 's/AllowTcpForwarding no/AllowTcpForwarding yes/g' /etc/ssh/sshd_config
+# Enable PAM so as to load /etc/environment via pam_env
+sed -i 's/#UsePAM no/UsePAM yes/g' /etc/ssh/sshd_config
 rc-service --ifstarted sshd reload
 
 # mount /sys/fs/cgroup