[MNG-7312] Revert ThreadLocal approach from MNG-6843 and MNG-7251

[michael-o]

Revert "[MNG-7251] Fix threadLocalArtifactsHolder leaking into cloned project"

This reverts commit 4e5b3d5.

Revert "[MNG-6843] Parallel build fails due to missing JAR artifacts in compilePath"

This reverts commit 76d5f0d.

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[michael-o]

@famod Same for 3.8.x

[michael-o]

Merged.