Recompile bindings fail without numpy

Description

When installing OTB 9.1.1 on an Ubuntu 24 docker, the binding recompilation fails if numpy is not installed. The problem here comes from the logs, staying that numpy is not found but can compile without, then a few commands later, it fails (see slurp pipeline https://github.com/CNES/slurp/actions/runs/15871696943/job/44749573482 )

To reproduce, install OTB 9.1.1 on a fresh ubuntu 24.04 docker.

Definition of Ready

Generic:

• If this issue is consequent, it is split into subtasks with priority and complexity evaluated. These subtasks should be linked to this issue. (To do on GitLab interface after writing this issue)
• Issue complexity evaluated
• Priority of issue evaluated
• If there is specific test data needed, it should be detailed and available
• If there is a specific documentation/specification need, it should be available to the development team
• Time during the sprint to realize this issue
• Blocking elements resolved (check if non-applicable, detail otherwise the resolved elements)

Definition of Done

Generic:

• No test regression on CI
• Code reviewed by peers
• Code cleaned, no "debug" traces or "TODO" comments kept.
• New code documented

Specific:

• Bindings compilation now works without numpy or fails before saying numpy is mandatory
• Cookbook updated if numpy installation is mandatory