[Bug report] Release scripts fail to work if you have multiple keys

### Version

main branch

### Describe what's wrong

The release script can grab the wrong key to sign the artefacts

### Error message and/or stacktrace

No error occurs but the release artefacts are signed by the wrong key.

### How to reproduce

Run release script when you have multiple keys under different email addresses.

### Additional context

_No response_

Start by locating the release script and reviewing how it selects a signing key when multiple email addresses are configured. Reproduce the issue with multiple keys, then verify that the selected key matches the intended release identity and that the release artifacts are signed by it.

Written by the indexing model from the issue text.