chore(backcompat): fix backcompat tests and tsconfig cleanup

[overbalance]

Follow up to #6225

Which problem is this PR solving?

Fix failing backcompat tests and cleanup config issues and duplicate code.

Short description of the changes

• Remove duplicate license header in otlp-transformer trace/internal.ts
• Fix backwards-compatibility tests to use proper tsconfig project references with tsc -p .
• Remove unnecessary allowJs from sampler-composite tsconfig files
• Update package-lock.json

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

• CI passes

Checklist:

• Followed the style guidelines of this project
• Unit tests have been added
• Documentation has been updated

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.40%. Comparing base (d33623e) to head (999c488).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #6232   +/-   ##
=======================================
  Coverage   95.40%   95.40%           
=======================================
  Files         317      317           
  Lines        9518     9518           
  Branches     2194     2194           
=======================================
  Hits         9081     9081           
  Misses        437      437           

Files with missing lines	Coverage Δ
...al/packages/otlp-transformer/src/trace/internal.ts	98.59% <ø> (ø)

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[pichlermarc]

I think we can fully drop the backcompat tests.
We don't support these versions anymore and we don't ever run them anywhere.

[pichlermarc]

I'll open a PR to kick out the unused backcompat tests.