github-ci fails to build nixos packages

[mixmasala]

in #55 I disable nixos build tests because although they pass locally, they fail to build in CI with this error:

build_other_linuxes	Build for Nix	2024-09-20T07:36:33.6471719Z building '/nix/store/25ijc05ya70h07i9569jm8r61j49bqw9-katzen-unstable-20240920073414-go-modules.drv'...
build_other_linuxes	Build for Nix	2024-09-20T07:36:33.9374960Z error: builder for '/nix/store/25ijc05ya70h07i9569jm8r61j49bqw9-katzen-unstable-20240920073414-go-modules.drv' failed with exit code 1;
build_other_linuxes	Build for Nix	2024-09-20T07:36:33.9376414Z        last 4 log lines:
build_other_linuxes	Build for Nix	2024-09-20T07:36:33.9377148Z        > Running phase: unpackPhase
build_other_linuxes	Build for Nix	2024-09-20T07:36:33.9378227Z        > unpacking source archive /nix/store/c30a1mz53jx5mbp2m5rk93745i2pv62h-source
build_other_linuxes	Build for Nix	2024-09-20T07:36:33.9379423Z        > cp: setting permissions for 'source': Operation not permitted
build_other_linuxes	Build for Nix	2024-09-20T07:36:33.9380851Z        > do not know how to unpack source archive /nix/store/c30a1mz53jx5mbp2m5rk93745i2pv62h-source
build_other_linuxes	Build for Nix	2024-09-20T07:36:33.9382876Z        For full logs, run 'nix log /nix/store/25ijc05ya70h07i9569jm8r61j49bqw9-katzen-unstable-20240920073414-go-modules.drv'.
build_other_linuxes	Build for Nix	2024-09-20T07:36:34.0858793Z error: 1 dependencies of derivation '/nix/store/89gffkm0fljnwal2f478bq6ma9m7fqal-katzen-unstable-20240920073414-env.drv' failed to build
build_other_linuxes	Build for Nix	2024-09-20T07:36:36.2549473Z make: *** [Makefile:59: docker-nix-base.stamp] Error 1
build_other_linuxes	Build for Nix	2024-09-20T07:36:36.2566840Z ##[error]Process completed with exit code 2.