Changes

releng: update version to 1.9.0 for upcoming release

Change-Id: I532e787950c6c8e6b3abadf0b2fc56e0cc3b1c60
Signed-off-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/c/tracecompass/tracecompass-test-traces/+/196237
Tested-by: Trace Compass Bot <tracecompass-bot@eclipse.org>
Tested-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Reviewed-by: Patrick Tasse <patrick.tasse@gmail.com>
Reviewed-by: Matthew Khouzam <matthew.khouzam@ericsson.com>