What is the bug or the crash?

The correct way to handle this is to always expose the algorithm, but at runtime raise a processing exception of the required library is not available (with an explanatory message).

This lets users still work on models using these tools, and gives them a friendly explanation as to why the to won't work (as opposed to it just getting missing)

See: #63092

cc @nyalldawson

Steps to reproduce the issue

• Build QGIS without PDAL support
• Open the processing toolbox
• PDAL processing are missing

Versions

QGIS 3.44

Supported QGIS version

• I'm running a supported QGIS version according to the roadmap.

New profile

• I tried with a new QGIS profile

Additional context

No response