[extensions.aws & sampler.aws] STJ tweaks

[CodeBlanch]

[This PR effectively reverts #2199]

Changes

• Remove STJ from OpenTelemetry.Extensions.AWS completely as it isn't used by any of the code.
• Put STJ back to 6.0.10 for net462 and netstandard2.0 targets in OpenTelemetry.Sampler.AWS because it relies on some of its behaviors (being able to deserialize to classes which do not have a public parameterless ctor).

Merge requirement checklist

• CONTRIBUTING guidelines followed (license requirements, nullable enabled, static analysis, etc.)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.75%. Comparing base (71655ce) to head (c0ed331).
Report is 532 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #2209       +/-   ##
===========================================
+ Coverage   73.91%   85.75%   +11.83%     
===========================================
  Files         267       15      -252     
  Lines        9615      393     -9222     
===========================================
- Hits         7107      337     -6770     
+ Misses       2508       56     -2452     

Flag	Coverage Δ
unittests-Extensions	88.63% <ø> (?)
unittests-Extensions.AWS	83.41% <ø> (?)

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see 268 files with indirect coverage changes