Condition validation schema is wrong

Verified context_mapping applies here. But shouldn't be mandatory.

Fixed config schema and related tests.

🏓 — missing some crucial info that will be necessary for this to become committable — right now, it's not clear whether this would break contrib/custom modules 😇

This was surfaced by 📌 PersonalizationSegment config entity Active .

🏓 Back to NR for feedback.
We can definitely be extra-safe and make uuid optional instead of removing it, but Occam's Razor says this was a copypasta 10 years ago.