Inconsistency in Docker documentation for GDB

After following the Docker documentation for [enabling GDB inside Docker](https://www.azerothcore.org/wiki/install-with-docker#procedures) (under `How to run the worldserver with gdb`), Docker Compose fails during the build because `gdb.conf` is missing.

The current guide still instructs users to copy `apps/startup-scripts/gdb.conf` into the image and to start `worldserver` with `gdb -x /azerothcore/gdb.conf`, but this file is no longer available after [#22418](https://github.com/azerothcore/azerothcore-wotlk/pull/22418). As a result, following the documentation leads to a build error instead of a working GDB setup.

It would be good to update the Docker GDB instructions so they match the current container setup and no longer reference the removed `gdb.conf` file.