mkDerivation: don't override meta.position

[pbsds]

This allows derivations to set it manually, which various builders and wrappers do

Description of changes

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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[pbsds]

Here is a diff of
nix-env --extra-experimental-features no-url-literals --option system x86_64-linux -f ./. -qaP --json --show-trace --meta --no-allow-import-from-derivation | jq 'to_entries[]|"\(.key): \(.value.meta.position)"' -r | sort

https://gist.github.com/pbsds/ccd24294cd6b77ea0c9f48d01b39abc5

[pbsds]

I can find both good and bad cases in the diff, i reckon most of the bad ones come from inherit (some-package) meta which now becomes a major foot-gun

[Aleksanaa]

There is a similar PR: #295973

[pbsds]

closing in favor of #295973