/etc/apache2/mods-available/mpm_worker.load is in apache2 2.4.25-3+deb9u6.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | # Conflicts: mpm_event mpm_prefork
LoadModule mpm_worker_module /usr/lib/apache2/modules/mod_mpm_worker.so
|