fix: add missing environment key in build-docker-compose.yaml

The CASC_RELOAD_TOKEN environment variable was missing its parent
'environment:' key, causing a YAML parsing error in updatecli.

This was likely introduced when GITPOD_WORKSPACE_URL variables were
removed, leaving the environment section malformed.

Author: gounthar

build-docker-compose.yaml

@@ -45,6 +45,7 @@ services:
     build: dockerfiles/.
     restart: on-failure
     # The CASC_RELOAD_TOKEN environment variable is used by the Jenkins controller to restart the Configuration as Code (JCasc) plugin configuration.
+    environment:
       - CASC_RELOAD_TOKEN=thisisnotsecure
     ports:
       - "8080:8080"