test: Adjust Vitest to only run on *.test files

Author: bennycode

src/sayHello.test.ts src/sayHello.test.mtssrc/sayHello.test.ts renamed to src/sayHello.test.mts

@@ -21,5 +21,6 @@ export default defineConfig({
     },
     environment: 'node',
     globals: true,
+    include: ['**/*.test.*'],
   },
 });