treewide: replace base64 encoded hashes

[LnL7]

Follow up on #89308.

Motivation for this change

These break compatibility with nix 2.0, see #89275.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[jtojnar]

Do you have a script for this I could set as pre-commit hook?

[LnL7]

The way this was generated is rather inefficient so I don't think it's really usable for that, but the plan is to enforce this in the evaluation checks. Otherwise we can't really maintain this.

[veprbl]

If I'm not mistaken, base64 hashes were introduced in 2.0 (NixOS/nix@c0015e8) and SRI in 2.2 (NixOS/nix@6024dc1). The problem with this PR is that it's not consistent with what node2nix generates automatically (e.g. in pkgs/development/node-packages/node-packages.nix).

[LnL7]

@veprbl Weird, I must have accidentally used an SRI or invalid base64 hash when testing.