changed 'workbench' from list to dict to match AssistantAgentConfig schema

[sanjiv27]

Why are these changes needed?

This fixes schema validation error caused by incorrectly setting "workbench" as a list in team.json. The framework expects "workbench" to be a dictionary.

Related issue number

None

Checks

• I've included any doc changes needed for https://microsoft.github.io/autogen/. See CONTRIBUTING.md 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.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.92%. Comparing base (e26bb1c) to head (b80c0aa).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #6830   +/-   ##
=======================================
  Coverage   79.92%   79.92%           
=======================================
  Files         233      233           
  Lines       18108    18108           
=======================================
  Hits        14473    14473           
  Misses       3635     3635           

Flag	Coverage Δ
unittests	79.92% <ø> (ø)

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[victordibia]

@sanjiv27 , can you provide more information on this?

The framework expects "workbench" to be a dictionary.

Can you provide a minimum reproducible example?

See here