bump ebd_toolchain from 0.12.5-a to 0.12.6

Author: hf-kklein

Diff for: ebd-tooling/docker-compose.yaml

@@ -4,7 +4,7 @@ services:
 
    scrape-and-plot: 
      build: . 
-     image: ghcr.io/hochfrequenz/ebd_toolchain:v0.12.5-a
+     image: ghcr.io/hochfrequenz/ebd_toolchain:v0.12.6
      # If you run into 'manifest unknown' during docker pull, try replacing `:latest` with `:v1.2.3`. 
      # where v1.2.3 is the latest version of the GHCR image, which can be found here: 
      # https://github.com/Hochfrequenz/ebd_toolchain/pkgs/container/ebd_toolchain