Fix python -c indentation + replace raw pip with uv pip

[Saikiran8]

1. Replace multiline Python -c snippets with heredocs to avoid indentation errors
2. Use uv pip download instead of system pip to ensure the correct interpreter

[ianhi]

Hi @Saikiran8 thanks for opening a PR. Can you please explain the motivation for the change from -c which seems to be wokring fine as is.

I agree that it might make sense to download with uv instead of normal pip.

[Saikiran8]

Thanks for the comment and consideration @ianhi .
python -c works, but multi-line -c blocks are fragile in YAML/shell contexts because whitespace and quoting are easy to accidentally change, which can lead to IndentationError or escaping issues.
I’ve run into this in the past when embedding secrets in EC2 user_data, where small indentation or quoting changes caused scripts to break in non-obvious ways. Using a heredoc may avoid this entire class of problems: the script body is passed verbatim, it’s easier to read and extend, and it’s the standard pattern for running multi-line shell or Python code in CI.