Format all Nix files using the officially approved formatter,
making the CI check introduced in the previous commit succeed:
nix-build ci -A fmt.check
This is the next step of the of the [implementation](https://github.com/NixOS/nixfmt/issues/153)
of the accepted [RFC 166](https://github.com/NixOS/rfcs/pull/166).
This commit will lead to merge conflicts for a number of PRs,
up to an estimated ~1100 (~33%) among the PRs with activity in the past 2
months, but that should be lower than what it would be without the previous
[partial treewide format](https://github.com/NixOS/nixpkgs/pull/322537).
Merge conflicts caused by this commit can now automatically be resolved while rebasing using the
[auto-rebase script](8616af08d9/maintainers/scripts/auto-rebase).
If you run into any problems regarding any of this, please reach out to the
[formatting team](https://nixos.org/community/teams/formatting/) by
pinging @NixOS/nix-formatting.
This essentially reverts 7ce8e7c4cf
asl20-llvm does not produce a valid SPDX ID, it produces a valid SPDX
Expression. However, this is not what the spdxId field promises.
This is relevant because we cannot produce valid SBOMs (e.g. CycloneDX)
using this field as the schemas for these SBOMs check that the IDs are
valid.
This change leaves us with consistently valid SPDX IDs at the cost
of slightly less convenience.
This is a variant composed of clause 1 and 3 of a BSD-Modified found in the
Linux kernel and this extra variant has the words "without modification" added
at the end of clause 1 either with or without a comma. It also lacks the
warranty disclaimer.
See <https://scancode-licensedb.aboutcode.org/bsd-no-disclaimer-unmodified.html>.
This is a follow-up to https://github.com/NixOS/nixpkgs/pull/325380 where @emilazy discovered that we have some typos in field names.
This refactoring wraps the implicit lib.licenses schema up in a factory function to ensure consistency.
While a more proper type checker like the one we use for meta checks would be better I didn't want to depend on that in more places.
In fact, we might want to make meta type checks more strict on the license field.
