requireFile: set unfree license by default

This avoids unfixable Hydra failures like
https://hydra.nixos.org/build/327183659.

doc/release-notes/rl-2611.section.md

@@ -13,6 +13,8 @@
 - `hurl` has been updated to `8.x.x` which has some breaking changes. See [upstream changelog](https://github.com/Orange-OpenSource/hurl/releases/tag/8.0.0) for details.
 - `python3Packages.django-health-check` has been updated to major version 4. See its [migration guide](https://codingjoe.dev/django-health-check/migrate-to-v4/) and [changelog](https://github.com/codingjoe/django-health-check/releases/tag/4.0.0) for breaking changes.
 
+- `requireFile` now sets `meta.license = lib.licenses.unfree` by default. Users of `requireFile`-based derivations that preserve this default will need to explicitly allow their evaluation as described in [](#sec-allow-unfree).
+
 ## Other Notable Changes {#sec-nixpkgs-release-26.11-notable-changes}
 
 <!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->

pkgs/build-support/trivial-builders/default.nix

@@ -908,6 +908,7 @@ rec {
         url ? null,
         message ? null,
         hashMode ? "flat",
+        meta ? { },
       }@args:
       assert (message != null) || (url != null);
       assert (sha256 != null) || (sha1 != null) || (hash != null);
@@ -951,6 +952,10 @@ rec {
           printf '%s' ${lib.escapeShellArg msg}
           exit 1
         '';
+        meta = {
+          license = lib.licenses.unfree;
+        }
+        // meta;
       }
       // (lib.optionalAttrs (name == null) {
         # The case of providing `url`, but not `name`. This has