fix: Fixes from integration tests

[jake-arkinstall]

When migrating some existing guppy notebooks, I found some things that slipped through the net:

• Array result types should be coerced to lists upon parsing
• The rotation extension was missing from selene-hugr-qis-compiler
• The environment setup for spawned selene backend processes was overriding host paths, leading to missing libstdc++.so.6 errors in some contexts.

These are addressed in this PR.