`deprecate_stop()` for `surv_reg()`

How long do we want to have `surv_reg()` sit in the warning stage of the deprecation? It's been warning on CRAN since *Apr 12, 2023*, so over a year now. Do we typically give people longer than that?

History:
- `deprecate_warn()` since Mar 30, 2023 on dev, released in parsnip 1.1.0 on *Apr 12, 2023*
- `deprecate_soft()` since Mar 23, 2021 on dev