pyright: Fix ErrorHandler taking Response | None

Signed-off-by: Bernhard Kaindl <bernhard.kaindl@cloud.com>

Author: bernhardkaindl

tests/httpserver_testcase.py

@@ -12,7 +12,7 @@
     from pytest_httpserver import HTTPServer
     from werkzeug.wrappers import Request, Response
 
-    ErrorHandler = Optional[Callable[[Request], Response]]
+    ErrorHandler = Optional[Callable[[Request], Response | None]]
 except ImportError:
     pytest.skip(allow_module_level=True)
     sys.exit(0)  # Let pyright know that this is a dead end