`parse_model() %>% tidypredict_fit()` broken for earth

[juliasilge]

We see this snapshot test right now:

Code
  tidypredict_fit(pm)
Output
  list()

I see that tidypredict_fit(model) and tidypredict_sql(model, dbplyr::simulate_odbc()) both work, but it seems like model %>% parse_model() %>% tidypredict_fit() does not work for earth.