chore(aws-util-test): exclude spec files from types build (#7084)

Author: kuhe

private/aws-util-test/tsconfig.types.json

@@ -6,5 +6,5 @@
     "declarationDir": "dist-types",
     "emitDeclarationOnly": true
   },
-  "exclude": ["test/**/*", "dist-types/**/*", "vitest.*.ts"]
+  "exclude": ["test/**/*", "**/*.spec.ts", "dist-types/**/*", "vitest.*.ts"]
 }