conftest: Migrate to new fixtures from swh-storage pytest plugin

Remove no longer needed swh_storage_backend_config override as storage
configuration is already defined in the swh-loader-core pytest plugin.

Use new swh_storage_config fixture in swh_loader fixture.

requirements-swh.txt

 swh.core >= 2.22.0
-swh.loader.core >= 5.18.3
+# swh.loader.core >= 5.18.3
+swh-loader-core @ git+https://gitlab.softwareheritage.org/swh/devel/swh-loader-core.git@refs/merge-requests/537/head#egg=swh.loader.core
 swh.model >= 6.13.0
 swh.scheduler >= 0.0.39
-swh.storage >= 2.4.1
+# swh.storage >= 2.4.1
+swh-storage @ git+https://gitlab.softwareheritage.org/swh/devel/swh-storage.git@refs/merge-requests/1154/head#egg=swh.storage

requirements-test.txt

 pytest >= 8.1
 pytest-mock
 requests_mock
-swh.loader.core[testing] >= 5.18.1
+# swh.loader.core[testing] >= 5.18.1
+swh-loader-core[testing] @ git+https://gitlab.softwareheritage.org/swh/devel/swh-loader-core.git@refs/merge-requests/537/head#egg=swh.loader.core
 swh.scheduler[testing] >= 0.5.0
-swh.storage[testing] >= 2.4.1
+# swh.storage[testing] >= 2.4.1
+swh-storage[testing] @ git+https://gitlab.softwareheritage.org/swh/devel/swh-storage.git@refs/merge-requests/1154/head#egg=swh.storage
 types-Deprecated
 types-click
 types-urllib3

swh/loader/git/tests/conftest.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
@@ -19,31 +19,9 @@ def git_lister():
 
 
 @pytest.fixture
-def swh_storage_backend_config(swh_storage_backend_config):
-    """Basic pg storage configuration with no journal collaborator
-    (to avoid pulling optional dependency on clients of this fixture)
-
-    """
-    return {
-        "cls": "filter",
-        "storage": {
-            "cls": "buffer",
-            "min_batch_size": {
-                "content": 10,
-                "content_bytes": 100 * 1024 * 1024,
-                "directory": 10,
-                "revision": 10,
-                "release": 10,
-            },
-            "storage": swh_storage_backend_config,
-        },
-    }
-
-
-@pytest.fixture
-def swh_loader_config(swh_storage_backend_config) -> Dict[str, Any]:
+def swh_loader_config(swh_storage_config) -> Dict[str, Any]:
     return {
-        "storage": swh_storage_backend_config,
+        "storage": swh_storage_config,
         "max_content_size": 100 * 1024 * 1024,
         "save_data_path": None,
     }