Configure webhooks for slack alerts

[anayeaye]

What

We are alerting CSDA on failed DAG runs and need to alert a channel for veda admins instead

channel: #veda-data-airflow

Note

• this will only work in prod

AC

• AWS Secrets Manager Env config added to use this channel
• veda data services support team is aware of channel/has access to follow

[botanical]

Related:
#376
#377