psdk: Add paramiko package dependency

The new `psdk-test` requests `paramiko` to run.

Signed-off-by: Frédéric Danis <frederic.danis@collabora.com>

test-cases/sdk-persistent-disk.yaml

@@ -13,6 +13,10 @@ metadata:
   description: "Tests that persistent disk can be used when upgrading the SDK."
 
   pre-conditions:
+    - Python3, e.g. see
+    - "~https://docs.conda.io/en/latest/miniconda.html"
+    - "`paramiko` package should be installed for Python3 by running:"
+    - $ pip3 install paramiko
     - "A virtual disk image (compressed or not) or a URL from which to get it from:"
     - "~https://images.apertis.org/"
     - "Clone of the apertis-tests repository:"