npmHooks.npmInstallHook: resolve symlinks when copying node_modules

[felschr]

Description of changes

Sometimes node_modules can contain symlinks that are currently being copied as is and can cause broken symlinks in the output. Symlinks are very common in projects using npm workspaces to reference other projects within the workspace.

I recently packaged protoc-gen-es but it currently fails with a runtime error where it complains about missing npm dependencies: #243432 (comment)
The issue can be resolved with the changes in this PR.

The issue for protoc-gen-es specifically could also be fixed in a postInstall script:

  postInstall = ''
    rm -rf $out/lib/node_modules/protobuf-es/node_modules/@bufbuild
    cp -rL node_modules/@bufbuild $out/lib/node_modules/protobuf-es/node_modules/
  '';

But to me it seems that this is a general issue that should ideally be solved in the npm install hook itself.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• 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/)
• 24.11 Release Notes (or backporting 23.11 and 24.05 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
• Fits CONTRIBUTING.md.

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[felschr]

Initially I thought this would classify as a mass rebuild but I just noticed it "only" affects 414 packages & previous changes to npm hooks also targeted master. So, I just switched the target branch.