Update installation instructions in pip.md to address PEP 668 compliance for Windows WSL2 with Ubuntu 24.04 or later.

[gaikwadrahul8]

Hi, Team
This PR will addresse the issue of outdated installation instructions for Windows WSL2 on the TensorFlow Pip Installation Guide.

Problem :
The existing instructions do not account for the changes introduced in Ubuntu 24.04 which enforces PEP 668. This specification treats Python environments as externally managed deprecating global installations of Python packages via pip.

The command python3 -m pip install tensorflow[and-cuda] no longer works on Ubuntu 24.04. User encounter the externally-managed-environment error unless they create and use a virtual environment.

The installation instructions have been updated to include steps for creating and using a virtual environment when working with TensorFlow on Ubuntu 24.04 or later. The steps ensure compatibility and compliance with PEP 668.

Updated Instructions :
For Ubuntu 24.04 in WSL2 the following steps are required to set up TensorFlow with CUDA:

1. sudo apt install python3-venv
2. python3 -m venv ~/tf
3. source ~/tf/bin/activate
4. python3 -m pip install tensorflow[and-cuda]

For more information please refer this issue tensorflow/tensorflow#79370 (comment) and it will fix that issue tensorflow/tensorflow#79370

if you've any feedback or suggestions for these changes please feel free to let me know. Thank you.

[haifeng-jin]

Thanks for the PR!
I don't have enough context on this.
Please let other reviewers review.