j: return exit code properly

fixes the bug of j tmt always returning 0

click in standalone_mode=False mode, as we use it in j, will not raise
the click.Exception.Exit but instead return the result as an integer.

this commit looks for the integer, and raisex the exception that
can be caught on the external try block.

(cherry picked from commit 88241fc)

Author: mangelajo

packages/jumpstarter-cli/jumpstarter_cli/j.py

@@ -26,7 +26,9 @@ async def cli():
             async with BlockingPortal() as portal:
                 with ExitStack() as stack:
                     async with env_async(portal, stack) as client:
-                        await to_thread.run_sync(lambda: client.cli()(standalone_mode=False))
+                        result = await to_thread.run_sync(lambda: client.cli()(standalone_mode=False))
+                        if isinstance(result, int) and result != 0:
+                            raise BaseExceptionGroup("CLI exit", [click.exceptions.Exit(result)])
         except BaseExceptionGroup as eg:
             # Handle exceptions wrapped in ExceptionGroup (e.g., from task groups)
             if exc := find_exception_in_group(eg, EnvironmentVariableNotSetError):
@@ -40,6 +42,9 @@ async def cli():
                 await cli()
             finally:
                 tg.cancel_scope.cancel()
+    except* click.exceptions.Exit as excgroup:
+        for exc in leaf_exceptions(excgroup):
+            sys.exit(exc.exit_code)
     except* click.ClickException as excgroup:
         for exc in leaf_exceptions(excgroup):
             cast(click.ClickException, exc).show()