修复：vscode “刷新 python 包时发生错误“。“Error refreshing packages Failed to run python -m pip list“
在虚拟环境（例如 conda）中使用 pip 安装一个包之后，vscode 发生如题报错。
这个错误是2025-12某一版 vscode/python 插件更新之后出现的。
观察 vscode “输出”，发现错误原因是 global 环境中没有安装 pip，说明新版本的python插件对全局 pip 也有依赖。
使用命令 `apt install python3-pip` 解决。
具体报错如下：
```
✓ Conda already active on launch, using default activation commands
==========================================
2025-12-23 09:01:25.016 [info] Found named environment: /root/miniforge3/envs/ds-vllm
2025-12-23 09:01:25.016 [info] Found prefix environment: /root/playground/attn_roofline_model/.env
2025-12-23 09:01:25.016 [info] Found named environment: /root/miniforge3/envs/attn_roofline_model
2025-12-23 09:01:25.016 [info] Found named environment: /root/miniforge3/envs/sglang
2025-12-23 09:01:25.016 [info] Found named environment: /root/miniforge3/envs/nano-vllm
2025-12-23 09:01:25.016 [info] Found named environment: /root/miniforge3/envs/PD-vllm
2025-12-23 09:01:25.016 [info] Found base environment: /root/miniforge3
2025-12-23 09:01:25.020 [info] Python API: Changed environment from ds-vllm (3.12.9) to ds-vllm (3.12.9) for: /root/playground/attn_roofline_model
2025-12-23 09:01:25.020 [info] Internal: Changed environment from ds-vllm (3.12.9) to ds-vllm (3.12.9) for: /root/playground/attn_roofline_model
2025-12-23 09:01:31.916 [info] Python API: Changed environment from undefined to base (3.12.8) for: global
2025-12-23 09:01:31.916 [info] Internal: Changed environment from undefined to base (3.12.8) for: global
2025-12-23 09:02:12.247 [info] Running: uv --version
2025-12-23 09:02:12.259 [info] Running: /bin/python3 -m pip list
2025-12-23 09:02:12.290 [info] python: /bin/python3: No module named pip
2025-12-23 09:02:12.295 [error] Error running pip list Failed to run python -m pip list
2025-12-23 09:02:12.295 [info] Package list retrieval attempted using pip, action can be done with uv if installed and setting `alwaysUseUv` is enabled.
2025-12-23 09:02:12.296 [error] Error refreshing packages Failed to run python -m pip list
```