addon-unit: dotted-path invocation + scheduled runs - #3

TMGimporter/libtmg.py imports the dbf PyPI package under a try/except
that only logs a warning on ImportError. When dbf is missing, the import
silently no-ops and later calls to Table(...) fail with NameError — which
is exactly how TMGimporter/tests/test_integration.py's setUpClass was
crashing in addon-unit runs (reported as _ErrorHolder in the JUnit
output).

Add dbf>=0.99.0 to both the local Dockerfile.ubuntu and the CI
requirements-test.txt so the dependency is present in every environment
where addon tests run. Local TMGimporter run now reports 175/175 OK
(was 157 pass + 1 setUpClass error).

Each addon declares its Python deps via requires_mod=[...] in its
.gpr.py, and Gramps' Addon Manager pip-installs exactly that list when
a user clicks Install (gramps/gui/plug/_windows.py __on_install_clicked
→ requirements.install → gen/utils/requirements.py). Mirror that
behaviour in the testbed so the test environment matches what an
end-user gets, and so new addon deps are picked up automatically
without a parallel list to maintain.

- scripts/ubuntu/run-addon-unit.sh: scan
  /workspace/addons-source/*/*.gpr.py for requires_mod declarations,
  union, pip-install each package individually (so a single build
  failure — pygraphviz without graphviz-dev, psycopg2 without
  libpq-dev — does not abort the batch).
- .github/workflows/addon-unit-tests.yml: same derivation step,
  running against the PR/fork checkout.
- docker/Dockerfile.ubuntu + requirements-test.txt: drop the
  hand-rolled `dbf` entry; it's now covered by the auto-derive, and
  keeping it would create a parallel source of truth that drifts.

Verified locally: union of 9 deps discovered across 8 addons
(boto3, dbf, life_line_chart, litellm, networkx, psycopg, psycopg2,
pygraphviz, svgwrite). 7 install cleanly; psycopg2 and pygraphviz fail
on missing system headers (known; affected addons' tests fail in
isolation). TMGimporter: 175/175 OK purely via auto-derived dbf.