stdenv: Pass -lN to GNU Make based on NIX_LOAD_LIMIT

[centromere]

Description of changes

On busy machines where Nix co-exists with other workloads, parallelism not work as intended. For example, consider a 64 core machine whose load average is 24 and where Nix is limited to 8 cores. By default, -j8 -l8 will be passed to GNU Make. Since the load average exceeds 8, no parallelism will take place despite the fact that 8 cores are available. In this case, load-limit should be set to 0 to prevent the -lN flag from being passed to GNU Make.

See also: #174473 NixOS/nix#6855

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 22.11 Release Notes (or backporting 22.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
  • (Release notes changes) Ran nixos/doc/manual/md-to-db.sh to update generated release notes
• Fits CONTRIBUTING.md.

[centromere]

Closing because of #192447.