[ci skip] Fix CrowdSec to monitor Traefik and add Slack notifications

- Switch acquisition from ingress-nginx to traefik namespace/pods
- Change collection from crowdsecurity/nginx to crowdsecurity/traefik
- Add Slack notification plugin for ban/captcha decisions
- Wire alertmanager_slack_api_url through to CrowdSec module

modules/kubernetes/main.tf

@@ -589,6 +589,7 @@ module "crowdsec" {
   crowdsec_dash_api_key          = var.crowdsec_dash_api_key
   crowdsec_dash_machine_id       = var.crowdsec_dash_machine_id
   crowdsec_dash_machine_password = var.crowdsec_dash_machine_password
+  slack_webhook_url              = var.alertmanager_slack_api_url
 }
 
 module "resume" {