docs(env): add clarification on missing pip in UV virtual environments

[DBinK]

Description

This PR fixes a documentation issue in the UV Environment section of the Python environment setup guide. When using uv venv, the created environment does not include pip, which leads to installation errors during Isaac Lab setup. On Ubuntu 22.04, users may also unintentionally invoke the system-wide pip (/usr/bin/pip or /usr/bin/pip3), resulting in packages being installed outside the virtual environment. This update adds a short clarification note and a command for installing pip manually inside the UV environment.

Fixes # (issue)

Type of change

• Documentation update

Screenshots

Checklist

• I have read and understood the [contribution guidelines](https://isaac-sim.github.io/IsaacLab/main/source/refs/contributing.html)
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have run the pre-commit checks with ./isaaclab.sh --format
• I have added tests that prove my fix is effective or that my feature works
• I have updated the changelog and the corresponding version in config/extension.toml
• I have added my name to CONTRIBUTORS.md or my name already exists there

[greptile-apps]

Greptile Overview

Greptile Summary

This PR addresses a documentation gap in the UV virtual environment setup instructions within the Isaac Lab installation guide. The change adds a clarification note and manual pip installation commands for UV environments, which don't include pip by default. The modification ensures users understand that UV environments created with uv venv require an explicit pip installation step, preventing installation failures and avoiding the risk of packages being installed to the system Python on Ubuntu 22.04. The documentation update is strategically placed in the Python virtual environment setup section and includes platform-specific instructions for both Linux and Windows systems.

Important Files Changed

Filename	Score	Overview
docs/source/setup/installation/include/pip_python_virtual_env.rst	5/5	Added clarification note and pip installation commands for UV virtual environments

Confidence score: 5/5

• This PR is extremely safe to merge with no risk of production issues
• Score reflects a simple, well-targeted documentation improvement that addresses a real user pain point with clear, accurate technical content
• No files require special attention as this is a straightforward documentation enhancement

[greptile-apps]

_{1 file reviewed, no comments}

_{Edit Code Review Agent Settings | Greptile}