[Bug]: Setting diagnostics and diagnostics_update_in_insert will throw a runtime error

### Is there an existing issue for this?

- [X] I have searched the existing issues

### What happened?

### What did you expect to happen?

without runtime error

### Config

```lua
options = {
-- ...
diagnostics = "nvim_lsp",
diagnostics_update_in_insert = true,
}
```

### Additional Information

The problem can be seen in the following link, maybe one of the two function calls are not longer supported in newer versions of neovim ?

Anyways it was easy to prevent the error by looking at the code but you may one to fix this ?

https://github.com/akinsho/bufferline.nvim/blob/main/lua/bufferline/config.lua#L65

### commit

_No response_