sdk/trace: Remove internaltest package

[Mojachieee]

Closes #6540
Closes #6535

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: Mojachieee / name: Joe Stephenson (92b050e, 9ccb453)
• ✅ login: pellared / name: Robert Pająk (0f963bb, d17fbc5)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.3%. Comparing base (8274f0e) to head (0f963bb).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #6846     +/-   ##
=======================================
+ Coverage   81.3%   82.3%   +0.9%     
=======================================
  Files        268     263      -5     
  Lines      24841   24416    -425     
=======================================
- Hits       20220   20097    -123     
+ Misses      4231    3937    -294     
+ Partials     390     382      -8     

see 4 files with indirect coverage changes

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