chore: no need to build docker here

Author: samrose

docker/nix/build_nix.sh

@@ -4,6 +4,5 @@ set -eou pipefail
 nix --version
 cd /workspace
 nix build .#psql_15/bin -o psql_15
-nix build .#psql_15/docker
 nix flake check -L 
 nix copy --to s3://nix-postgres-artifacts?secret-key=nix-secret-key ./psql_15