Python - Autocommit two ways of setting it

### What would you like help with?

In python's adbc-driver-manager there are two ways of setting `autocommit` in the `connect` method one is through the `conn_kwargs` the other is through `autocommit`.
the first uses `set`Option _pre-init_ and the second uses a _post-init_ `setOption`.

in general, i think a pre-init is preferable and the connect is able to use it. My question is why not?

context: it doesn't hurt functionality but because `autocommit` can be set in two ways at the same time can sometimes cause unexpected behavior / be confusing.

Start in the adbc-driver-manager Python connect method and compare the conn_kwargs pre-init setOption path with the autocommit post-init setOption path. Trace how both options are applied and document or test the resulting behavior; done requires a clear decision about whether the duplicate setting paths should remain.

Written by the indexing model from the issue text.