chore: enhance typing and documentation in tasks module (#3467)

- Disable E501 line length linting rule
- Add Google-style docstrings to tasks leaf file
- Modernize typing and docs in task_output.py
- Improve typing and documentation in conditional_task.py

pyproject.toml

@@ -131,6 +131,7 @@ select = [
     "I001",   # sort imports
     "I002",   # remove unused imports
 ]
+ignore = ["E501"]  # ignore line too long
 
 [tool.mypy]
 exclude = ["src/crewai/cli/templates", "tests"]