[jdk21u-dev] RFR: 8331999: BasicDirectoryModel/LoaderThreadCount.java frequently fails on Windows in CI

[Andrew Lu]

I backport this for parity with 21.0.5-oracle.

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Commit messages:
 - Backport ffbdfffbc702253f32fa45dc1855b663c72074a6

Changes: https://git.openjdk.org/jdk21u-dev/pull/741/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=741&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8331999
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/741.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/741/head:pull/741

PR: https://git.openjdk.org/jdk21u-dev/pull/741