RFR: CODETOOLS-7903102: Remove obsolete traces of references to JavaHelp

[Jonathan Gibbons]

Please review a build-only fix to remove obsolete references to the old JavaHelp system, which was removed back in 2016. [CODETOOLS-7901673](https://bugs.openjdk.java.net/browse/CODETOOLS-7901673)

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Commit messages:
 - CODETOOLS-7903102: Remove obsolete traces of references to JavaHelp

Changes: https://git.openjdk.java.net/jtreg/pull/58/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jtreg&pr=58&range=00
  Issue: https://bugs.openjdk.java.net/browse/CODETOOLS-7903102
  Stats: 73 lines in 25 files changed: 0 ins; 46 del; 27 mod
  Patch: https://git.openjdk.java.net/jtreg/pull/58.diff
  Fetch: git fetch https://git.openjdk.java.net/jtreg pull/58/head:pull/58

PR: https://git.openjdk.java.net/jtreg/pull/58