build(test-plain-python-missing-stack-frames): Migrate to uv and pyproject.toml

[ericapisani]

Summary

• Replace pip/requirements.txt with uv/pyproject.toml
• Update run.sh to use uv run
• Remove legacy requirements.txt

Refs PY-2470

🤖 Generated with Claude Code

[linear-code]

PY-2470

[sentry]

Bug: The script uses uv immediately after installation, but the installer doesn't update the PATH for the current shell session, causing a 'command not found' error.
_{Severity: HIGH}

Suggested Fix

After installing uv, either add its installation directory (e.g., ~/.local/bin) to the PATH for the current session (e.g., export PATH="$HOME/.local/bin:$PATH") or invoke the binary using its absolute path. This ensures the command can be found within the same script execution.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent. Verify if this is a real issue. If it is, propose a fix; if not, explain why it's
not valid.

Location: test-plain-python-missing-stack-frames/run.sh#L5-L9

Potential issue: The script installs `uv` via a piped shell command. The installer
modifies shell profile files (e.g., `.bashrc`) to add the `uv` binary's directory to the
system `PATH`. However, these changes do not affect the `PATH` of the currently running,
non-interactive shell script. As a result, the subsequent call to `uv run python
main.py` will fail with a 'command not found' error because the shell's `PATH`
environment variable has not been updated. This causes the script to fail in any
environment where `uv` is not pre-installed.

_{Did we get this right? 👍 / 👎 to inform future reviews.}