Fixing the timout flag for kubectl exec command

This change fixes a command-line parameter in a script that sets up initial data for a GitLab system. The script was using an outdated parameter name (--timeout) when running commands inside a container, and it's been updated to use the correct current parameter name (--request-timeout). This is a simple compatibility fix to ensure the script works properly with the current version of the underlying tools.

Related to #52 (closed) &198 (closed)