cmdLineTester_libpathTestRtfChild fails on "headless" riscv64

[andrew-m-leonard]

Ref: #5852 (comment)
Adoptium builds riscv64 headless, and thus test cmdLineTester_libpathTestRtfChild fails:

00:21:34   [ERR] Exception in thread "main" java.lang.UnsatisfiedLinkError:
 Can't load library:
 /home/jenkins/workspace/Test_openjdk17_hs_sanity.functional_riscv64_linux_rerun/
jdkbinary/j2sdk-image/lib/libawt_xawt.so

This needs excluding at: https://github.com/eclipse-openj9/openj9/blob/a843c7e581d01c14e70c5c6847e1428000e9c7de/test/functional/cmdLineTests/libpathTest/playlist.xml#L58

[sophia-guo]

eclipse-openj9/openj9#20962 (comment)

Test should not enable for headless platforms as DefaultStyledDocument styledDoc = new DefaultStyledDocument(); requires libawt_xawt.so. Close this issue.