Otherwise if in Nix context we can accidentally use GNU stat which
results in a different output due to different command line flags:
```
[nix-shell:~/status-mobile]$ stat -Lf "%Sg" "/nix/store"
stat: cannot read file system information for '%Sg': No such file or directory
File: "/nix/store"
ID: 10000110000001a Namelen: ? Type: apfs
Block size: 4096 Fundamental block size: 4096
Blocks: Total: 242837545 Free: 199242283 Available: 199242283
Inodes: Total: 7971454780 Free: 7969691320
```
And it should be just owner group name or ID. Which in turn results in:
```
Unknown Nix installtion type!
```
Signed-off-by: Jakub Sokołowski <jakub@status.im>
Otherwise Nix produces warnings like this:
```
warning: ignoring untrusted substituter 'https://nix-cache.status.im/', you are not a trusted user.
```
Since adding users to `trusted-users` essentially gives them `root`:
>Adding a user to trusted-users is essentially equivalent to giving that user root access to the system.
> — https://nixos.org/manual/nix/stable/command-ref/conf-file.html#conf-trusted-users
A more kosher approach might be to just add the cache config itself globally.
Signed-off-by: Jakub Sokołowski <jakub@status.im>
Jakub Sokołowski