fix "the attribute version is obsolete, it will be ignored"

sni · sni · commit 9a9ec9177284 · 2024-08-28T10:18:45.000+02:00
diff --git a/t/docker-compose.yml b/t/docker-compose.yml
@@ -1,5 +1,3 @@
-version: '3.7'
-
 services:
   debian-icewm:
     image: "local/debian-icewm-vnc"
