Change alert Slack channel to g_mlops-alerts

It's currently making some noise in the g_ai_framework Slack channel that disturbs communications for non-engineering folks.

We just move the alerts to g_mlops-alerts as the central place to get the AI related alerts. The channel is already used by Code Creation and Model Validation group.

Related to Alert to g_ai_framework Slack channel for llm_c... (!6561 - merged)