Fix ty check and pin Sphinx for docs

Author: tobiasraabe

pyproject.toml

@@ -33,7 +33,7 @@ docs = [
     "matplotlib",
     "myst-parser",
     "nbsphinx",
-    "sphinx",
+    "sphinx<9",
     "sphinx-autobuild",
     "sphinx-click",
     "sphinx-copybutton",

src/pytask_parallel/wrappers.py

@@ -217,7 +217,7 @@ def _render_traceback_to_string(
     traceback = Traceback(exc_info, show_locals=show_locals)
     segments = console.render(cast("Any", traceback), options=console_options)
     text = "".join(segment.text for segment in segments)
-    return (*exc_info[:2], text)  # ty: ignore[invalid-return-type]
+    return (*exc_info[:2], text)
 
 
 def _handle_function_products(