nix-installer: Create a workflow to propose new releases

.github/workflows/propose-release.yml

@@ -0,0 +1,41 @@
+on:
+  workflow_dispatch:
+    inputs:
+      reference-id:
+        type: string
+        required: true
+      version:
+        type: string
+        required: true
+      nix-version:
+        type: string
+        required: true
+
+concurrency:
+  group: ${{ github.workflow }}
+  cancel-in-progress: true
+
+jobs:
+  propose-release:
+    uses: DeterminateSystems/propose-release/.github/workflows/workflow.yml@main
+    permissions:
+      id-token: "write"
+      contents: "write"
+      pull-requests: write
+    with:
+      reference-id: ${{ inputs.reference-id }}
+      version: ${{ inputs.version }}
+      extra-commands-early: |
+        for fname in $(find ./tests/fixtures -name '*.json'); do
+          cat "$fname" \
+            | jq '.version = $version' --arg version "$version" \
+            > "$fname.next"
+          mv "$fname.next" "$fname"
+          git add "$fname"
+        done
+        git commit -m "Update test fixtures with the new nix-installer version" || true
+
+        sed -ix 's#https://flakehub.com/f/DeterminateSystems/nix/=.*";#https://flakehub.com/f/DeterminateSystems/nix/=${{ inputs.nix-version }}";#' ./flake.nix
+        rm flake.nixx
+        git add flake.nix
+        git commit -m "Update Nix release to ${{ inputs.nix-version }}"

.github/workflows/release-tags.yml

@@ -4,9 +4,9 @@ concurrency:
   group: release
 
 on:
-  push:
-    tags:
-      - "v*.*.*"
+  release:
+    types:
+      - released
 
 permissions:
   contents: write # In order to upload artifacts to GitHub releases
@@ -31,6 +31,7 @@ jobs:
       cache-key: release-aarch64-darwin-artifacts-${{ github.sha }}
 
   release:
+    environment: production
     runs-on: ubuntu-latest
     needs:
       - build-x86_64-linux

CONTRIBUTING.md

@@ -348,8 +348,8 @@ You can also remove your `$HOME/nix-installer-wsl-tests-temp` folder whenever yo
 
 This package uses [Semantic Versioning](https://semver.org/). When determining the version number for a new release refer to Semantic Versioning for guidance. You can use the `check-semver` command alias from within the development environment to validate your changes don't break semver.
 
-To cut a release, run `./prepare-release.sh 0.0.1` inside `nix develop`.
-This script will:
+To cut a release, run the GitHub Actions workflow `propose-release.yml`.
+This will:
 
 - Create a release branch from `main` (`git checkout -b release-v0.0.1`)
   - Release PRs should not contain any installer-related changes which require review