installers, tests: remove --preserve=mode from cp invocations (backport #13427)#13430

edolstra merged 1 commit into2.30-maintenanceNixOS/nix:2.30-maintenancefrom

mergify/bp/2.30-maintenance/pr-13427NixOS/nix:mergify/bp/2.30-maintenance/pr-13427Copy head branch name to clipboard