qemu: fix build when desktop file does not exist (#110721)
qemu: fix build when desktop file does not exist (#110721)

The qemu-user variants as used by binfmt emulation through
`(lib.systems.elaborate lib.systems.examples.aarch64-multiplatform).emulator pkgs`
does not install a .desktop file since qemu 5.2.0. This change allows
the build to continue if deletion of the desktop file fails.
NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs