v2.3.1 — revert ollama-cuda NUM_PARALLEL bump from v2.3.0

Patch on top of v2.3.0. OLLAMA_NUM_PARALLEL default goes back to 1
because ollama's scheduler pins embedding models to 1 slot anyway
(server/sched.go:414-417), making the 50 default misleading for the
use case its docs advertised.

For parallel embedding throughput in ollama, batch the inputs via
input:[...] on /v1/embeddings — that's the correct mechanism.

pibox stays at v0.7.0.