tf-a-main: disable visualization jobs

The production Jenkins instance appears to be unable to spin up an
instance of Ubuntu 22.04, which the staging instance is able to do.
Disable these jobs until we identify why.

Change-Id: I5d98406f4786586087ef19328495bbb5c4dbc3cf
Signed-off-by: Chris Kay <chris.kay@arm.com>
1 file changed