Drop use of pifpaf and the "db" pytest mark

We've been using pytest-postgresql for... a year (4117d5ab).

swh/scheduler/tests/test_celery_tasks.py

@@ -50,7 +50,6 @@ def test_multiping(swh_app, celery_session_worker):
         assert ("OK (kw={'i': %s})" % i) in results
 
 
-@pytest.mark.db
 def test_scheduler_fixture(swh_app, celery_session_worker, swh_scheduler):
     "Test that the scheduler fixture works properly"
     task_type = swh_scheduler.get_task_type("swh-test-ping")
@@ -67,7 +66,6 @@ def test_scheduler_fixture(swh_app, celery_session_worker, swh_scheduler):
         AsyncResult(id=task["backend_id"]).get()
 
 
-@pytest.mark.db
 def test_task_return_value(swh_app, celery_session_worker, swh_scheduler):
     task_type = swh_scheduler.get_task_type("swh-test-add")
     assert task_type
@@ -82,7 +80,6 @@ def test_task_return_value(swh_app, celery_session_worker, swh_scheduler):
     assert value == 42
 
 
-@pytest.mark.db
 def test_task_exception(swh_app, celery_session_worker, swh_scheduler):
     task_type = swh_scheduler.get_task_type("swh-test-error")
     assert task_type

swh/scheduler/tests/test_scheduler.py

@@ -13,8 +13,6 @@ from typing import Any, Dict
 
 from arrow import utcnow
 
-import pytest
-
 from .common import tasks_from_template, TEMPLATES, TASK_TYPES
 
 
@@ -24,7 +22,6 @@ def subdict(d, keys=None, excl=()):
     return {k: d[k] for k in keys if k not in excl}
 
 
-@pytest.mark.db
 class TestScheduler:
     def test_get_priority_ratios(self, swh_scheduler):
         assert swh_scheduler.get_priority_ratios() == {

tox.ini

@@ -6,14 +6,12 @@ extras =
   testing
 deps =
   pytest-cov
-  pifpaf
   dev: ipdb
 setenv =
   LC_ALL=C.UTF-8
   LC_CTYPE=C.UTF-8
   LANG=C.UTF-8
 commands =
-    pifpaf run postgresql -- \
       pytest --doctest-modules \
   !slow: --hypothesis-profile=fast \
   slow:  --hypothesis-profile=slow \