Remove outdated azd deploy workflow (azure-dev.yaml) #365

The .github/workflows/azure-dev.yaml workflow ("Deploy with azd") is outdated and should be removed.

Problems:

• It runs an azd deployment automatically on every push to main, which is not appropriate for this sample.
• It references repository secrets (secrets.*) for configuration, which is the old pattern and no longer how these samples are configured.

Please delete .github/workflows/azure-dev.yaml.