RFR: 8366805: Skip failing MenuDoubleShortcutTest on macOS

[Jayathirth D V]

Skip macOS specific MenuDoubleShortcutTest.macSceneComesBeforeMenuBar() test until the issue is fixed under [JDK-8364405](https://bugs.openjdk.org/browse/JDK-8364405)

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Commit messages:
 - 8366805: Skip failing MenuDoubleShortcutTest on macOS

Changes: https://git.openjdk.org/jfx/pull/1896/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1896&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8366805
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jfx/pull/1896.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1896/head:pull/1896

PR: https://git.openjdk.org/jfx/pull/1896