[Fix] mypy related warning

.github/workflows/pythonapp.yml

@@ -29,7 +29,7 @@ jobs:
           python -m pip install --upgrade pip
           python -m pip install ruff==0.14.1 mypy==1.19.1 uv pytest types-tqdm
           python -m pip install "ta-lib==0.6.4" --index-url https://pypi.vnpy.com
-          python -m pip install -e ".[dev]" "polars>=1.26.0" "scipy>=1.15.2" statsmodels matplotlib
+          python -m pip install -e ".[dev]" "polars>=1.26.0" "scipy>=1.15.2" "pyarrow>=19.0.1" statsmodels matplotlib
           python -m pip install vnpy_sqlite
 
       - name: Lint