Fix missing AL-Go-Helper.ps1 import in CalculateArtifactNames (#2230)

### ❔What, Why & How

PR #2221 refactored `CalculateArtifactNames.ps1` to call
`Get-CurrentBranchName` but didn't add the dot-source import of
`AL-Go-Helper.ps1` where that function is defined. This breaks the CICD
workflow at artifact name calculation.

Fix: add the standard import at the top of the script.

```powershell
. (Join-Path -Path $PSScriptRoot -ChildPath "../AL-Go-Helper.ps1" -Resolve)
```

### ✅ Checklist

- [ ] Add tests (E2E, unit tests)
- [ ] Update RELEASENOTES.md
- [ ] Update documentation (e.g. for new settings or scenarios)
- [ ] Add telemetry

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: mazhelez <43066499+mazhelez@users.noreply.github.com>