[jdk17u-dev] RFR: 8278893: Parallel: Remove GCWorkerDelayMillis

[Richard Reingruber]

This backport is a dependency for the backport of https://bugs.openjdk.org/browse/JDK-8310031
Applies cleanly.
Risk is low: it's a small change and only unused debug code is removed.

Local CI Testing:
The fix passed our CI testing (e.g. 2024-02-22): JTReg tests: tier1-4 of hotspot and jdk. All of Langtools and jaxp. JCK, SPECjvm2008, SPECjbb2015, Renaissance Suite, and SAP specific tests (also with ParallelGC).
Testing was done with fastdebug builds on the main platforms and also on Linux/PPC64le.

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Depends on: https://git.openjdk.org/jdk17u-dev/pull/2226

Commit messages:
 - 8278893: Parallel: Remove GCWorkerDelayMillis

Changes: https://git.openjdk.org/jdk17u-dev/pull/2227/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=2227&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8278893
  Stats: 21 lines in 3 files changed: 0 ins; 21 del; 0 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/2227.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/2227/head:pull/2227

PR: https://git.openjdk.org/jdk17u-dev/pull/2227