Set minimum required xeus-lite version to 3.2.1

[mcbarton]

Description

Please include a summary of changes, motivation and context for this PR.

If you look at Emscripten xeus-cpp recipe in Emscripten forge here https://github.com/emscripten-forge/recipes/blob/b34db3abcffbec2b24b97d4fd8def6c4d31888e4/recipes/recipes_emscripten/xeus-cpp/recipe.yaml#L22C19-L22C24 , it has a minimum version of xeus-lite of 3.2.1. This PR makes it is so that cmake also has this minimum required version

Fixes # (issue)

Type of change

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• Bug fix
• New feature
• Added/removed dependencies
• Required documentation updates

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81.78%. Comparing base (7ecb686) to head (7a9fc12).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #339   +/-   ##
=======================================
  Coverage   81.78%   81.78%           
=======================================
  Files          20       20           
  Lines         950      950           
  Branches       87       87           
=======================================
  Hits          777      777           
  Misses        173      173           

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