update cuda integration test example to new sfgconfig api

integration/test_cuda.py

-from pystencils import Target, CreateKernelConfig, create_kernel, no_jit
+from pystencils import Target, CreateKernelConfig, no_jit
 from lbmpy import create_lb_update_rule, LBMOptimisation
-from pystencilssfg import SourceFileGenerator, SfgConfiguration
-from pystencilssfg.lang.cpp import mdspan_ref
+from pystencilssfg import SourceFileGenerator, SfgConfig
 
-sfg_config = SfgConfiguration(
-    output_directory="out/test_cuda",
-    outer_namespace="gen_code",
-    impl_extension="cu"
-)
+sfg_config = SfgConfig()
+sfg_config.extensions.impl = "cu"
+sfg_config.output_directory = "out/test_cuda"
+sfg_config.outer_namespace = "gen_code"
 
 with SourceFileGenerator(sfg_config) as sfg:
     gen_config = CreateKernelConfig(target=Target.CUDA, jit=no_jit)
@@ -15,6 +13,4 @@ with SourceFileGenerator(sfg_config) as sfg:
     update = create_lb_update_rule()
     kernel = sfg.kernels.create(update, "lbm_update", gen_config)
 
-    sfg.function("lb_update")(
-        sfg.call(kernel)
-    )
+    sfg.function("lb_update")(sfg.call(kernel))