Update to latest ixmp4 testing sqlite setup

tests/conftest.py

@@ -10,6 +10,7 @@
 import pandas as pd
 import pytest
 from httpx import ConnectError
+from ixmp4.conf.base import PlatformInfo
 from ixmp4.core import Platform
 from ixmp4.data.backend import SqliteTestBackend
 
@@ -267,11 +268,20 @@ def plot_stackplot_df():
 
 @pytest.fixture(scope="function")
 def test_platform():
-    platform = Platform(_backend=SqliteTestBackend())
+    sqlite = SqliteTestBackend(
+        PlatformInfo(name="sqlite-test", dsn="sqlite:///:memory:")
+    )
+    sqlite.setup()
+
+    platform = Platform(_backend=sqlite)
     platform.regions.create(name="World", hierarchy="common")
     platform.units.create(name="EJ/yr")
+
     yield platform
 
+    sqlite.close()
+    sqlite.teardown()
+
 
 @pytest.fixture(scope="session")
 def conn():