chore: upgrade to 7.3.0+v1.154.0

compose.yml

@@ -128,10 +128,6 @@ services:
     secrets:
       - db_password
     environment:
-      # postgres:18 relocated the default PGDATA to /var/lib/postgresql/18/docker.
-      # Pin it to the legacy path so pgautoupgrade finds the existing cluster on the
-      # mounted volume and upgrades it in place, instead of init'ing an empty one.
-      - PGDATA=/var/lib/postgresql/data
       - LC_COLLATE=C
       - LC_CTYPE=C
       - POSTGRES_DB=synapse