chore: adds pre-commit (#7242)

### What problem does this PR solve?

Sometimes after we commit the code and open the PR the CI pipeline fails
in Ruff checks. Including a pre-commit we can identify this problem
early and avoid time loss.

### Type of change

- [ ] Bug Fix (non-breaking change which fixes an issue)
- [X] New Feature (non-breaking change which adds functionality)
- [ ] Documentation Update
- [ ] Refactoring
- [ ] Performance Improvement
- [ ] Other (please describe):

README_zh.md

@@ -270,7 +270,7 @@ docker build --platform linux/amd64 --build-arg NEED_MIRROR=1 -f Dockerfile -t i
 1. 安装 uv。如已经安装，可跳过本步骤：
 
    ```bash
-   pipx install uv
+   pipx install uv pre-commit
    export UV_INDEX=https://mirrors.aliyun.com/pypi/simple
    ```
 
@@ -280,6 +280,7 @@ docker build --platform linux/amd64 --build-arg NEED_MIRROR=1 -f Dockerfile -t i
    git clone https://github.com/infiniflow/ragflow.git
    cd ragflow/
    uv sync --python 3.10 --all-extras # install RAGFlow dependent python modules
+   pre-commit install
    ```
 
 3. 通过 Docker Compose 启动依赖的服务（MinIO, Elasticsearch, Redis, and MySQL）：