Fix the docker build error due to an old symfon/cache version

[BentiGorlich]

Fixes

[php builder-composer 7/7] RUN composer run-script --no-dev post-install-cmd && chmod +x bin/console && sync:
0.627
0.627 Run composer recipes at any time to see the status of your Symfony recipes.
0.627
0.658 Executing script cache:clear [KO]
3.345 [KO]
3.345 Script cache:clear returned with error code 255
3.345 !! PHP Fatal error: Declaration of Symfony\Component\Cache\Traits\Redis6ProxyTrait::hSet($key, $fields_and_vals): Redis|int|false must be compatible with Redis::hSet(string $key, mixed ...$fields_and_vals): Redis|int|false in /var/www/mbin/vendor/symfony/cache/Traits/Redis6ProxyTrait.php on line 30
3.345 !!

3.345 Script @auto-scripts was called via post-install-cmd

failed to solve: process "/bin/sh -c composer run-script --no-dev post-install-cmd && chmod +x bin/console && sync" did not complete successfully: exit code: 255

[melroy89]

Thx