The `Duration` argument in `get_models` has been unused for over a year.

The `complete` function is also unused and it has fallen behind in new
feature additions such as Authorization support. This used to exist
because ollama didn't support tools in streaming mode, `with_tools` also
existed because of that. Now however there is no reason to keep this
around.

`ChatResponseDelta ` had unnecessary `#[allow(unused)]` macros since the
fields are marked `pub`. Using `#[expect(unused)]` would've caught this.

Release Notes:

- N/A