cli: Replace scheduler temporary backend by memory one

Scheduler temporary backend has been removed in favor of a
more efficient memory backend.

requirements-swh.txt

 swh.core[db] >= 3.4.0
-swh.scheduler >= 2.5.0
+swh.scheduler >= 2.7.0

requirements-test.txt

@@ -2,7 +2,7 @@ pandas
 pytest >= 8.1
 pytest-mock
 requests_mock
-swh-scheduler[testing] >= 2.4.0
+swh-scheduler[testing] >= 2.7.0
 types-beautifulsoup4
 types-click
 types-pyyaml

swh/lister/cli.py

-# Copyright (C) 2018-2021  The Software Heritage developers
+# Copyright (C) 2018-2024  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
@@ -72,10 +72,10 @@ def run(ctx, lister, options):
     if "scheduler" not in config:
         logger.warning(
             "No scheduler configuration detected, using a temporary instance "
-            "with postgresql backend instead."
+            "with a memory backend instead."
         )
 
-        config["scheduler"] = {"cls": "temporary"}
+        config["scheduler"] = {"cls": "memory"}
 
     print(get_lister(lister, **config).run())