Only warn for missing config if init was successful

src/testing-utils.ts

@@ -1031,6 +1031,7 @@ export function createTestConfig(overrides: Partial<Config>): Config {
       overlayModeSetExplicitly: false,
       repositoryProperties: {},
       enableFileCoverageInformation: true,
+      successfullyInitialised: false,
     } satisfies Config,
     overrides,
   );