add motherduck examples for duckdb plugin

[dansola]

Recently the duckdb plugin was updated here: flyteorg/flytekit#2680

This PR updates the flyte docs.

[samhita-alla]

@dansola can you take a look at the failed checks?

[dansola]

@dansola can you take a look at the failed checks?

good call. I think there was a failing lint test (which I fixed) and also an import error for DuckDBProvider in the duckdb test. I think this must be because we haven't cut a release with the newest version. are we able to do quick releases for plugins or does it have to follow main flytekit releases?

Also now it looks like all test fail because of a github actions deprecation.

[samhita-alla]

@dansola how about you add the flytekit beta version whichever has the updated plugin to duckdb requirements?