Insecure default setting for Server Pro installed via Overleaf toolkit

Overleaf is a web-based collaborative LaTeX editor. When installing Server Pro using the Overleaf Toolkit from before 2024-07-17 or legacy docker-compose.yml from before 2024-08-28, the configuration for LaTeX compiles was insecure by default, requiring the administrator to enable the security features via a configuration setting (SIBLING_CONTAINERS_ENABLED in Toolkit, SANDBOXED_COMPILES in legacy docker-compose/custom deployments). If these security features are not enabled then users have access to the sharelatex container resources (filesystem, network, environment variables) when running compiles, leading to multiple file access vulnerabilities, either directly or via symlinks created during compiles. The setting has now been changed to be secure by default for new installs in the Toolkit and legacy docker-compose deployment. The Overleaf Toolkit has been updated to set SIBLING_CONTAINERS_ENABLED=true by default for new installs. It is recommended that any existing installations using the previous default setting migrate to using sibling containers. Existing installations can set SIBLING_CONTAINERS_ENABLED=true in config/overleaf.rc as a mitigation. In legacy docker-compose/custom deployments SANDBOXED_COMPILES=true should be used.