Exit on error in .github/workflows/nextmv.yaml

[cnpryer]

I didn't see a license. So feel free to close this out.

I used this repository as a reference to set up my CI/CD for my nextmv apps. I noticed that my nextmv app push step was silently failing.

This PR just adds set -e to that step.

💽 Starting build for Nextmv application.
🔨 Running pre-push command: "/usr/bin/bash -c uv export --package routing-pipeline --format requirements-txt --output-file requirements.txt --no-dev --no-editable --no-hashes".
bash: line 1: uv: command not found
Error running pre-push command: exit status 127.
Created version
{
  "id": "3bbb87a",
  "application_id": "routing-pipeline",
  "name": "3bbb87a",
  "description": "Version 3bbb87a",
  "executable": {
    "id": "3bbb87a",
    "user_email": "...",
    "uploaded_at": "2025-03-10T15:06:13.086069805Z",
    "requirements": {
      "executable_type": "python",
      "runtime": "ghcr.io/nextmv-io/runtime/python:3.11"
    }
  }
}

# app.yaml
type: python
runtime: ghcr.io/nextmv-io/runtime/python:3.11
pre-push: uv export --package routing-pipeline --format requirements-txt --output-file requirements.txt --no-dev --no-editable --no-hashes
python:
  pip-requirements: requirements.txt
files:
  - routing_pipeline/*.py
  - main.py
  - key.json

So my pre-push step was failing, but the step would continue on. Ended up confusing me on nextmv.io when my version was pointed at an older release.