fix: convert Github to GitHub

[LongOddCode]

bug: https://msazure.visualstudio.com/Microsoft%20Teams%20Extensibility/_sprints/taskboard/Teams%20Extensibility%20E2E%20Team/Microsoft%20Teams%20Extensibility/Dilithium/CY24Q3/2Wk/2Wk09%20(Jul%2028%20-%20Aug%2010)?workitem=28802729

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.47%. Comparing base (0f9211b) to head (793381c).
Report is 1 commits behind head on dev.

Additional details and impacted files

@@            Coverage Diff             @@
##              dev   #12145      +/-   ##
==========================================
+ Coverage   89.46%   89.47%   +0.01%     
==========================================
  Files         571      572       +1     
  Lines       33596    33613      +17     
  Branches     6419     6433      +14     
==========================================
+ Hits        30057    30076      +19     
  Misses       1583     1583              
+ Partials     1956     1954       -2     

Files	Coverage Δ
...code-extension/src/handlers/copilotChatHandlers.ts	97.59% <ø> (ø)

... and 4 files with indirect coverage changes