RFR: 8347302: Mark test tools/jimage/JImageToolTest.java as flagless

[Leonid Mesnik]

Test
test/jdk/tools/jimage/JImageToolTest.java
ignore vm flags and should be marked as flagless.

It is needed to don't try to run this test with virtual test thread factory.

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Commit messages:
 - 8347302

Changes: https://git.openjdk.org/jdk/pull/22992/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22992&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8347302
  Stats: 2 lines in 1 file changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/22992.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22992/head:pull/22992

PR: https://git.openjdk.org/jdk/pull/22992