RFR: 8357406: Remove usages of jdk.tracePinnedThreads system property from httpclient tests

[SendaoYan]

On Wed, 21 May 2025 10:34:09 GMT, Jaikiran Pai <jpai at openjdk.org> wrote:

> Can I please get a review of this test-only change which removes the usage of the outdated `jdk.tracePinnedThreads` system property from the httpclient tests? This addresses https://bugs.openjdk.org/browse/JDK-8357406.
> 
> As noted in the linked issue, this system property is no longer supported by the Virtual Threads implementation in the JDK.
> 
> These tests continue to pass after this change.

LGTM

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Marked as reviewed by syan (Committer).

PR Review: https://git.openjdk.org/jdk/pull/25347#pullrequestreview-2859903402