Remove the nix CI (#542)

.github/workflows/run-builds.yml

@@ -1,38 +0,0 @@
-name: "nix CI"
-on:
-  push:
-    branches: [master]
-  workflow_dispatch:
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@v3
-    - uses: cachix/install-nix-action@v18
-      with:
-        nix_path: nixpkgs=channel:nixos-unstable
-    - id: cache-restore
-      uses: actions/cache/restore@v3
-      with:
-        path: nix-store.nar
-        key: nix-store-nar-${{ hashFiles('flake.lock') }}
-    - if: steps.cache-restore.outputs.cache-hit == 'true'
-      run: |
-        nix-store --import < nix-store.nar
-        rm nix-store.nar
-
-    - run: nix develop
-    - run: nix build
-    - run: nix build .#clerk
-
-    - name: dump store
-      if: steps.cache-restore.outputs.cache-hit == 'false'
-      run: nix-store --export $(nix-store -qR $(nix print-dev-env --json | jq .variables.prefix.value -r)) > nix-store.nar
-    - name: save current cache
-      if: steps.cache-restore.outputs.cache-hit == 'false'
-      uses: actions/cache/save@v3
-      id: cache
-      with:
-        path: nix-store.nar
-        key: nix-store-nar-${{ hashFiles('flake.lock') }}
-

.github/workflows/update-flake-lock.yml

@@ -1,30 +0,0 @@
-name: update lock files
-
-on:
-  schedule:
-    - cron: '0 0 * * 1'
-  workflow_dispatch:
-
-jobs:
-  update:
-    runs-on: ubuntu-latest
-    steps:
-      - name: install nix
-        uses: cachix/install-nix-action@v15
-      - name: checkout
-        uses: actions/checkout@v3
-      - name: update flake.lock
-        run: |
-          nix flake update
-      - name: check catala builds
-        run: |
-          nix build
-      - name: check clerk builds and catala test-suite passes
-        run:  |
-          nix build .#clerk
-      - name: commit changes
-        uses: EndBug/add-and-commit@v9
-        with:
-          author_name: adelaett
-          author_email: 90894311+adelaett@users.noreply.github.com
-          message: "Update lock files"

INSTALL.md

@@ -28,7 +28,27 @@ by running:
 
     ./_build/install/default/bin/catala --help
 
-### With nix
+### With opam
+
+The Catala compiler is written using OCaml. First, you have to install `opam`,
+OCaml's distribution and package manager. Follow the [instructions on the `opam`
+website](https://opam.ocaml.org/doc/Install.html).
+
+Next, you will need to use the correct version of OCaml. Catala has been tested
+with OCaml compiler versions that are at least 4.14.0. To switch to OCaml 4.14.0,
+just use:
+
+    opam switch 4.14.0
+
+If you get a `No switch 4.14.0 is currently installed` error message, follow
+the hint and enter `opam switch create 4.14.0`.
+
+
+### With nix (best effort)
+
+> [!WARNING]
+> Nix support for the Catala compiler is now on a "best effort" basis due to maintenance demands.
+> Interested users are encouraged to contribute via pull requests.
 
 The repository provides nix files to build or develop the catala compiler.
 
@@ -58,20 +78,6 @@ To develop catala's compiler using vscode using ocaml's [lsp](https://microsoft.
 
 The nix build is updated weekly by an automatic github action.
 
-### With opam
-
-The Catala compiler is written using OCaml. First, you have to install `opam`,
-OCaml's distribution and package manager. Follow the [instructions on the `opam`
-website](https://opam.ocaml.org/doc/Install.html).
-
-Next, you will need to use the correct version of OCaml. Catala has been tested
-with OCaml compiler versions that are at least 4.14.0. To switch to OCaml 4.14.0,
-just use:
-
-    opam switch 4.14.0
-
-If you get a `No switch 4.14.0 is currently installed` error message, follow
-the hint and enter `opam switch create 4.14.0`.
 
 ## Dependencies