RFR: 8357673: remove test serviceability/jvmti/vthread/TestPinCaseWithCFLH

[Serguei Spitsyn]

The test `test/hotspot/jtreg/serviceability/jvmti/vthread/TestPinCaseWithCFLH/TestPinCaseWithCFLH.java` was contributed by an external contributor to exercise the `-Djdk.tracePinnedThreads=full` system property when a `javaagent` was involved. The `jdk.tracePinnedThreads` system property is no longer supported by Virtual Threads implementation in mainline. That system property was dropped as part of https://github.com/openjdk/jdk/pull/21565 in JDK 24.
This update removes the test which is not needed anymore.

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Commit messages:
 - 8357673: remove test serviceability/jvmti/vthread/TestPinCaseWithCFLH

Changes: https://git.openjdk.org/jdk/pull/25424/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25424&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8357673
  Stats: 77 lines in 1 file changed: 0 ins; 77 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/25424.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25424/head:pull/25424

PR: https://git.openjdk.org/jdk/pull/25424