nixos-test-driver: fix handling of type-check-disabled case

f1bcb61731 did not handle this correctly,
causing failures (e.g. https://hydra.nixos.org/build/326659503/nixlog/2/tail)

nixos/lib/test-driver/src/test_driver/__init__.py

@@ -174,7 +174,11 @@ def generate_driver_symbols() -> None:
             vlans=[],
             global_timeout=0,
             enable_ssh_backdoor=False,
-            test_script=Path("testScriptWithTypes"),
+            test_script=(
+                Path("testScriptWithTypes")
+                if (Path("testScriptWithTypes").is_file())
+                else Path("testScriptFile")
+            ),
         ),
         out_dir=Path(),
         logger=CompositeLogger([]),

nixos/lib/testing/driver.nix

@@ -85,6 +85,8 @@ let
                 testScriptWithTypes
         ''}
 
+        echo -n "$testScript" > testScriptFile
+
         cp "${config.driverConfiguration.test_script}" $out/test-script
 
         ln -s ${testDriver}/bin/nixos-test-driver $out/bin/nixos-test-driver