horizon recently switch nodeset for a few jobs from
focal to debian-bullseye  as per the runtime of 2023.1
cycle but looks like 'heat-dashboard-integration-tests'
start failing because the firefox package for debian-bullseye
is missing in ``bindep.txt``. This patch updates the ``bindep.txt``
file to sync with the horizon.
This patch adds basic tests to verify that heat-dashboard is
installed and could be opened.
heat-dashboard-integration-tests job is added in a