Merged pnpm6 experiment into pnpm detector

[pauld-msft]

Pnpm6 has gone through a week or so of experimentation after being introduced with #1110 and has been validated to work as expected.

This pull request:

• removes the experiment
• merges the pnpm6 changes into pnpm detector, using the suggested format from this comment
• increments Pnpm detector version from 5 -> 6

[codecov]

Codecov Report

Attention: Patch coverage is 94.16667% with 7 lines in your changes are missing coverage. Please review.

Project coverage is 76.3%. Comparing base (9c3b0d5) to head (bfd9c50).

Files	Patch %	Lines
...ion.Detectors/pnpm/PnpmComponentDetectorFactory.cs	93.4%	4 Missing and 1 partial ⚠️
...ComponentDetection.Detectors/pnpm/Pnpm5Detector.cs	94.1%	0 Missing and 2 partials ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #1145     +/-   ##
=======================================
+ Coverage   76.1%   76.3%   +0.1%     
=======================================
  Files        255     255             
  Lines      11306   11298      -8     
  Branches    1135    1134      -1     
=======================================
+ Hits        8614    8622      +8     
+ Misses      2357    2344     -13     
+ Partials     335     332      -3     

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[github-actions]

👋 Hi! It looks like you modified some files in the Detectors folder.
You may need to bump the detector versions if any of the following scenarios apply:

• The detector detects more or fewer components than before
• The detector generates different parent/child graph relationships than before
• The detector generates different devDependencies values than before

If none of the above scenarios apply, feel free to ignore this comment 🙂

[cobya]

Changes look good to me 👍