[bitnami/openldap] Check pw-sha2 library output

[jotamartos]

Description of the change

Verify that the pw-sha2.so library generates a valid output.

Benefits

This helps us confirm that the solution works in all distros

Possible drawbacks

None

Applicable issues

Additional information

[jotamartos]

I tested the change manually and it worked as expected

root@5489b2360726:/tmp/goss# ./goss-linux-amd64 --vars vars.yaml -g openldap.yaml v
.....................

Total Duration: 0.032s
Count: 21, Failed: 0, Skipped: 0
root@5489b2360726:/tmp/goss#

[jotamartos]

Tests succeeded here: https://github.com/bitnami/containers/actions/runs/6095508034/job/16541271737?pr=47483