docker-compose: remove unsuppported option `volumes[].tmpfs.mode`

CHANGELOG.md

@@ -5,6 +5,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Fixed
+- docker-compose: remove unsuppported option `volumes[].tmpfs.mode`
 
 ## [1.0.0] - 2021-06-20
 ### Added

docker-compose.yml

@@ -18,7 +18,6 @@ services:
       target: /tmp # entrypoint.sh
       tmpfs:
         # nosuid,nodev,noexec added by default
-        mode: '1777'
         size: 16k # default config has approx 5kB
     ports:
     - '4001:4001'