backends: fix TestSerialisation.suite annotations
It's a `str[]` not `str`
@@ -159,7 +159,7 @@ class ExecutableSerialisation:
self.subproject = ''
class TestSerialisation:
- def __init__(self, name: str, project: str, suite: str, fname: T.List[str],
+ def __init__(self, name: str, project: str, suite: T.List[str], fname: T.List[str],
is_cross_built: bool, exe_wrapper: T.Optional[programs.ExternalProgram],
needs_exe_wrapper: bool, is_parallel: bool, cmd_args: T.List[str],
env: build.EnvironmentVariables, should_fail: bool,
