* switch default LLM from a model that is going away
If an api key is provided, Grist can use an LLM as an assistant
for writing formulas. The LLM can be self-hosted or an external
service. The default external service is OpenAI. This commit
freshens the default model used, if this feature is enabled,
since the existing one is going away. Benchmarking suggests the
results are generally better, though not dramatically so.
The feature of falling back on a longer context model is no longer
as important, but is retained since it could be useful for self-hosters.
* update long context model tests
a45a7f9fda