We are moving location of symlinks for build derivations for `gcroots`
from `/nix/var/nix/gcroots/per-user` to `.nix-gcroots` in the repo to
avoid errors like this caused by profile migration in `2.14` release:
```
error: creating directory '/nix/var/nix/gcroots/per-user/joe': Permission denied
```
For more details see: https://github.com/NixOS/nix/issues/8564
To upgrade without using `make nix-purge` use `make nix-upgrade`.
Related infra change:
https://github.com/status-im/infra-ci/commit/37c6ce47
Signed-off-by: Jakub Sokołowski <jakub@status.im>
Jakub Sokołowski
c5df51d944