Add the ReasoningAgent to CI

[Hk669]

Why are these changes needed?

Add ReasoningAgent to CI

Related issue number

N/A

Checks

• I've included any doc changes needed for https://docs.ag2.ai/. See https://docs.ag2.ai/docs/contributor-guide/documentation to build and test documentation locally.
• I've added tests (if relevant) corresponding to the changes introduced in this PR.
• I've made sure all auto checks have passed.

[marklysze]

Thanks @Hk669, Is the graphviz package installing as part of the tests? The last two tests are failing for me (and although they are mocking graphviz, it will still need it installed).

[Hk669]

let me try to fix the tests.

[Hk669]

@marklysze can you take a look at the changes, i think these should fix this installation problem for the CI tests.

[marklysze]

Thanks @Hk669!

[sonichi]

@Hk669 I'm holding off merging this PR. This CI should be made as optional and only triggered when necessary.
cc @BabyCNM @qingyun-wu @davorrunje @marklysze
Update: this PR doesn't do benchmarking, so it's OK to merge now.