.oniro-ci: find DEPLOY_DIR, not TMPDIR

Some jobs care about images and licenses, those look at the
$TMPDIR/deploy, taking some effort to find the correct tmpdir while
hard-coding the deploy dir. Take a shortcut and query for the right
variable (DEPLOY_DIR).

This allows non-trivial layouts with DEPLOY_DIR and TMPDIR placed on
distinct filesystems, for efficiency.

Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@huawei.com>