Remove quotes from octal value in reference/compose-file/services.md

Fixes #22590

Author: b-

content/reference/compose-file/services.md

@@ -1889,7 +1889,7 @@ services:
         target: server.cert
         uid: "103"
         gid: "103"
-        mode: "0o440"
+        mode: 0o440
 secrets:
   server-certificate:
     file: ./server.cert