Playbooks - remove all `remote_user` references

geant/gap_ansible/playbooks/base_config_checks.yaml

geant/gap_ansible/playbooks/check_ibgp.yaml

geant/gap_ansible/playbooks/iptrunks_checks.yaml

geant/gap_ansible/playbooks/iptrunks_migration.yaml

geant/gap_ansible/playbooks/update_ibgp_mesh.yaml

roles/check_demarcation_point/tasks/checks.yaml

roles/check_demarcation_point/tasks/compare.yaml

roles/check_demarcation_point/tasks/create_file.yaml

roles/check_demarcation_point/tasks/get_ifstatus.yaml

roles/check_demarcation_point/tasks/get_optical_levels.yaml

roles/check_demarcation_point/tasks/main.yml

roles/check_demarcation_point/vars/main.yml

roles/check_demarcation_point/vars/optical_thresholds.yml