1a2e7a19

By: Lucien Huber <im@lcnbr.ch>

share integration test features and compiled artifacts

Use one Python-enabled integration test context with disjoint archive filters.
Retain public outputs and per-crate cache boundaries; remove duplicate
scheduling and record local inventory, runtime, and derivation validation.

User request:
also could we unify features so that we can share artefacts (remember we just want tests to run)