chore: upgrade @edx/frontend-component-header to ^8.2.1

[awais-ansari]

Summary

Bumps @edx/frontend-component-header from ^6.2.1 to ^8.2.1

Test plan

Verify header renders correctly on course pages
Verify no visual regressions in the header across learner-facing views

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.17%. Comparing base (ac3e829) to head (aff6134).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1345   +/-   ##
=======================================
  Coverage   81.17%   81.17%           
=======================================
  Files          51       51           
  Lines         834      834           
  Branches      242      241    -1     
=======================================
  Hits          677      677           
  Misses        150      150           
  Partials        7        7           

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