Reword "we"s to "I"s for consistency
Reword "we"s to "I"s for consistency

This script uses multiple forms of the first-person POV:
1. "We" to refer to the Nix team (https://github.com/NixOS/nix/blob/1e7c796e66a692cd097b155bd0a60fedf20d554f/scripts/install-multi-user.sh#L72)
2. "We" to refer to the combination of the installation script & the user/executor (https://github.com/NixOS/nix/blob/1e7c796e66a692cd097b155bd0a60fedf20d554f/scripts/install-multi-user.sh#L710)
3. "We" to refer to the installation script alone (https://github.com/NixOS/nix/blob/1e7c796e66a692cd097b155bd0a60fedf20d554f/scripts/install-multi-user.sh#L602)
4. "I" to refer to the installation script alone (https://github.com/NixOS/nix/blob/1e7c796e66a692cd097b155bd0a60fedf20d554f/scripts/install-multi-user.sh#L200)

Since I prefer POV 4 to POV 3, this changes all instances of POV 3 to POV 4.
rycee/nix,rycee/nix,rycee/nix,rycee/nix,NixOS/nix,NixOS/nix,rycee/nix,NixOS/nix,NixOS/nix,NixOS/nix