Fix: Icons are not aligned vertically.

[xionnon]

Why are these changes needed?

Related issue number

Closes #6366

Checks

• I've included any doc changes needed for https://microsoft.github.io/autogen/. See https://github.com/microsoft/autogen/blob/main/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 78.29%. Comparing base (881cd6a) to head (d8e3f35).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #6369   +/-   ##
=======================================
  Coverage   78.29%   78.29%           
=======================================
  Files         221      221           
  Lines       16184    16184           
=======================================
  Hits        12672    12672           
  Misses       3512     3512           

Flag	Coverage Δ
unittests	78.29% <ø> (ø)

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