stdenv: log hooks as they run (take II)

[Qyriad]

Description of changes

A second take at #290081, which changes the stdenv builder to log setup and build hooks as they run, but which was reverted for the extra logging during the internals of nix-shell -p. This PR does the same logging, but to $NIX_LOG_FD instead, which is echoed during any normal build, but not during the internals of nix-shell -p.

cc @philiptaron @RaitoBezarius from the last PR

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/)
• 24.05 Release Notes (or backporting 23.05 and 23.11 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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[Qyriad]

Rebased on latest staging

[RaitoBezarius]

I would recommend to wait for the next staging cycle as the current one is the last NixOS 24.05's one.

[philiptaron]

Code looks good to me. I'm currently building a representative sample of nixpkgs, and I see the hook logging.

[Qyriad]

Now that the last staging cycle for 24.05 has been done, this PR should be ready

[paparodeo]

LGTM tested with nix-shell on master

$ curl -L https://github.com/NixOS/nixpkgs/pull/310387.patch | git apply
$ cat test.sh
#!/usr/bin/env nix-shell
#! nix-shell -i bash --pure
#! nix-shell -p hello
hello
$ NIX_PATH=nixpkgs=`pwd` ./test.sh  | tee stdout.log
[...]
$ cat stdout.log
Hello, world!

[philiptaron]

Let's rumble! Thanks to everyone for getting this through and thanks to @Qyriad for authoring it. I really like how it helps make what's going on with hooks more understandable.