nix-related CI failure

[thpani]

Integration tests fail in CI with

error: could not set permissions on '/nix/var/nix/profiles/per-user' to 755: Operation not permitted

Probably caused by cachix/install-nix-action#148

For a full log, see this job

[thpani]

@shonfeder do you remember why we set install_url here?

apalache-chai/.github/workflows/main.yml

Lines 130 to 133 in 9e51e69

	- name: Install Nix
	uses: cachix/install-nix-action@v14.1
	with:
	install_url: https://nixos-nix-install-tests.cachix.org/serve/vij683ly7sl95nnhb67bdjjfabclr85m/install

[shonfeder]

I don’t remember, but following the link on the comment on that step I found this comment from past me actions/cache#324 (comment)

it seems I took this from a workaround at a link which no longer exists :)

probably the nix setup here needs to be updated and reworked.