haskell.compiler.ghcjs: remove at 8.10.7

Author: sternenseemann

doc/release-notes/rl-2511.section.md

@@ -46,6 +46,8 @@
 
 - `conduwuit` was removed due to upstream ceasing development and deleting their repository. For existing data, a migration to `matrix-conduit`, `matrix-continuwuity` or `matrix-tuwunel` may be possible.
 
+- The GHCJS 8.10.7, exposed via `haskell.compiler.ghcjs` and `haskell.compiler.ghcjs810`, has been removed. Downstream users should migrate their projects to the new JavaScript backend of GHC proper which can be used via `pkgsCross.ghcjs` from Nixpkgs.
+
 - `gnome-keyring` no longer ships with an SSH agent anymore because it has been deprecated upstream. You should use `gcr_4` instead, which provides the same features. More information on why this was done can be found on [the relevant GCR upstream PR](https://gitlab.gnome.org/GNOME/gcr/-/merge_requests/67).
 
 - `stdenv.mkDerivation` and other derivation builders that use it no longer allow the value of `env` to be anything but an attribute set, for the purpose of setting environment variables that are available to the [builder](https://nix.dev/manual/nix/latest/store/derivation/#builder) process. An environment variable called `env` can still be provided by means of `mkDerivation { env.env = ...; }`, though we recommend to use a more specific name than "env".