fix: switch over to list for threading

compose.yml

@@ -66,12 +66,11 @@ services:
     secrets:
       - db_password
     environment:
-      POSTGRES_DB: synapse
-      POSTGRES_USER: synapse
-      POSTGRES_PASSWORD_FILE: /run/secrets/db_password
-      # https://matrix-org.github.io/synapse/latest/postgres.html#set-up-database
-      POSTGRES_INITDB_ARGS: "--encoding=UTF-8 --lc-collate=C --lc-ctype=C"
-      STACK_NAME: ${STACK_NAME}
+      - POSTGRES_DB=synapse
+      - POSTGRES_INITDB_ARGS="--encoding=UTF-8 --lc-collate=C --lc-ctype=C"
+      - POSTGRES_PASSWORD_FILE=/run/secrets/db_password
+      - POSTGRES_USER=synapse
+      - STACK_NAME
     networks:
       - internal
     healthcheck: