[lldb] Skip delay-init test when run on pre-macOS 15

The test has a check that the static linker supports the new option,
but it assumed the Xcode 16 linker also meant it was running on
macOS 15 and the dynamic linker would honor dependencies flagged
this way.  But Xcode 16 can be run on macOS 14.5, so we need to
skip the test in that combination.