Fix issue caused by chromadb error type change

[thinkall]

Why are these changes needed?

The new chromadb version has changed the error type of get_collection, thus caused issue #3551 . This PR fixes the issue by adding the new error type to the exception handling in create_collection method. We also updates related docs so that users can bypass the error when they're using the current version of AutoGen.

Related issue number

Closes #3551

Checks

• I've included any doc changes needed for https://microsoft.github.io/autogen/. See https://microsoft.github.io/autogen/docs/Contribute#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.

[tonyliang]

For those who are late to the game and still facing this issue, I am able to bypass the issue with this combo:

chroma-hnswlib==0.7.6
chromadb==0.5.5