Update the product validation task

The built-in task_validate_products is now replaced by task_validate_geant_products such that it removes the step that requires us to add modify_note to all products. This workflow is not used by us, and therefore doesn't need to be tested for.

docs/source/module/workflows/tasks/index.rst

+``gso.workflows.tasks``
+=======================
+
+.. automodule:: gso.workflows.tasks
+   :members:
+   :show-inheritance:
+
+Submodules
+----------
+
+.. toctree::
+   :maxdepth: 2
+   :titlesonly:
+
+   validate_geant_products