Currently, it is not possible to configure `apps.plugin` via NixOS
option `services.netdata.configDir."apps_groups.conf"`. This is because
`apps.plugin` explicitly does not follow symbolic links when reading its
configuration from apps_groups.conf[^ref].
This change will copy that file instead of symlinking to address this.
Fixes #255161
[^ref]: 3849e70f93/src/collectors/apps.plugin/apps_plugin.c (L679)