[BUG] Cannot locally launch agent without requirements.txt

[gombosg]

Describe the bug
A clear and concise description of what the bug is.

When there is no requirements.txt, only pyproject.toml, then local launch fails.

To Reproduce
Steps to reproduce the behavior:

1. Have a minimal repo without requirements.txt (e.g. just remove it if it already exists)
2. Use agentcore launch --local

Expected behavior
A clear and concise description of what you expected to happen.

It should run the code in e.g. main.py or throw an error that requirements.txt doesn't exist.

Error Output

error: Adding requirements from a `pyproject.toml` is not supported in `uv run`

Environment:

• Python 3.13
• uv 0.9.10
• starter toolkit 0.1.133

Additional context
Add any other context about the problem here.

See here:

Using pyproject.toml, setup.py, or setup.cfg files is not allowed.

This code accepts pyproject.toml but it won't be accepted by uv as a requirements source.

Workaround: create a requirements.txt file manually:
uv pip compile pyproject.toml -o requirements.txt