nix: update nix-fallback-paths to 2.28.3

{

  x86_64-linux = "/nix/store/pzwdmrz94mya45m1jnsf294c0g3cwy9m-nix-2.28.2";

  i686-linux = "/nix/store/vzqxry2dwq9nzr2y0jk1q7qv3ygv14m1-nix-2.28.2";

  aarch64-linux = "/nix/store/52zak9psh00w8c8iz8x0ny33in5wwr83-nix-2.28.2";

  riscv64-linux = "/nix/store/rkggav1j9wb55zc8jsl1vg81s831aqj8-nix-riscv64-unknown-linux-gnu-2.28.2";

  x86_64-darwin = "/nix/store/afwsvhzqf936zx5v4i7ynqah2qhq7qyj-nix-2.28.2";

  aarch64-darwin = "/nix/store/djcysgb0pgrigaqfnmraviv6nix786zi-nix-2.28.2";

  x86_64-linux = "/nix/store/pfh6bq2wxbpp3xz5sinymmp44n505zh8-nix-2.28.3";

  i686-linux = "/nix/store/nfxdfb9zcrm9sqkw8xhdqs7vcvrwp1k2-nix-2.28.3";

  aarch64-linux = "/nix/store/7w6fj8s7h4pcmx38m1f51xd93ywizm4i-nix-2.28.3";

  riscv64-linux = "/nix/store/nnynd5vfd6pf9jkp13bmj44rlrd61l3h-nix-riscv64-unknown-linux-gnu-2.28.3";

  x86_64-darwin = "/nix/store/rdxbh5m09c9i2s7zkh7b8g6mnrpmaa19-nix-2.28.3";

  aarch64-darwin = "/nix/store/wjrdsqbaial7pl9vfhqc7cpzd9lqcr6a-nix-2.28.3";

}