Refs #31196 -- Installed postgis_raster extension on PostGIS 3+.

tests/gis_tests/rasterapp/migrations/0001_setup_extensions.py

@@ -0,0 +1,18 @@
+from django.db import connection, migrations
+
+if connection.features.supports_raster:
+    from django.contrib.postgres.operations import CreateExtension
+
+    pg_version = connection.ops.postgis_version_tuple()
+
+    class Migration(migrations.Migration):
+        # PostGIS 3+ requires postgis_raster extension.
+        if pg_version[1:] >= (3,):
+            operations = [
+                CreateExtension('postgis_raster'),
+            ]
+        else:
+            operations = []
+else:
+    class Migration(migrations.Migration):
+        operations = []