Revert "[Monitoring] Monitor DNS IPv6 connectivity"

Because IPv6 is not enabled inside Docker containers and it's more complicated than I thought, see later

This reverts commit b5054091.

pica-metrologie/vmagent-prom.yml

@@ -175,11 +175,8 @@ scrape_configs:
     static_configs:
       - targets:
         - 91.224.148.84 #ns01.picasoft.net
-        - 2a03:7220:8080:5400::1
         - 91.224.148.85 #ns02.picasoft.net
-        - 2a03:7220:8080:5500::1
         - 51.158.76.113 #ns03.picasoft.net
-        - 2001:bc8:4400:2b00::31:d03
     relabel_configs:
     - source_labels: [__address__]
       target_label: __param_target