gcc: do not --disable-bootstrap, create libgcc output, or create checksum output on Darwin

[ghost]

I broke gcc on Darwin.

This fixes it.

[ghost]

# before 209870
$ git reset --hard 867440983fa5c542a677e30cee581e5f37531052
HEAD is now at 867440983fa5 Merge staging-next into staging
$ nix-instantiate . -A gcc --argstr localSystem aarch64-darwin
/nix/store/hvxzhiy871sq7jsiq3qhywzp37sga0r4-gcc-wrapper-12.2.0.drv

# after 209870 plus 224944
$ git fetch https://github.com/NixOS/nixpkgs/ pull/209870/head; git reset --hard FETCH_HEAD
From https://github.com/NixOS/nixpkgs
 * branch                      refs/pull/209870/head -> FETCH_HEAD
HEAD is now at 6c209e862e18 emacs: path fixes resulting from libgccjit changes
$ git fetch https://github.com/NixOS/nixpkgs/ pull/224944/head
From https://github.com/NixOS/nixpkgs
 * branch                      refs/pull/224944/head -> FETCH_HEAD
$ git cherry-pick FETCH_HEAD
Auto-merging pkgs/development/compilers/gcc/11/default.nix
[pr/fix-amjoseph-stupidity 8465718e1212] gcc: do not --disable-bootstrap, create libgcc output, or create checksum output on Darwin
 Date: Wed Apr 5 21:31:17 2023 -0700
 4 files changed, 4 insertions(+), 4 deletions(-)
$ nix-instantiate . -A gcc --argstr localSystem aarch64-darwin
/nix/store/hvxzhiy871sq7jsiq3qhywzp37sga0r4-gcc-wrapper-12.2.0.drv