Automate draft release creation

The GitHub workflow creates a new draft release for the given tag. It collects all pre- and post-release tasks mentioned in PR descriptions of PRs that were merged into `next` since it diverged from `main`.

Author: bogsi17

.github/workflows/draft-new-release.yml

@@ -0,0 +1,33 @@
+name: draft-new-release.yml
+run-name: Draft release notes for ${{ inputs.release_tag }}
+permissions:
+  contents: write
+
+on:
+  workflow_dispatch:
+    inputs:
+      release_tag:
+        required: true
+        description: Release tag
+
+jobs:
+  create-release-notes:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+      - name: Generate release notes
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: script/draft_new_release.sh ${{ inputs.release_tag }}
+      - name: Create GitHub Release
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          gh release create "${{ inputs.release_tag }}" \
+            --title "Draft release ${{ inputs.release_tag }}" \
+            --notes-file release_notes.md \
+            --draft
+

script/draft_new_release.sh

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+#!/usr/bin/env bash
+
+# This script creates a new draft release and creates a template for the release notes. 
+# It extracts pre-release and post-release tasks from pull request descriptions.
+# The required syntax is:
+# Pre-Release:
+# - Task 1
+# - Task 2
+# Post-Release:
+# - Task 3
+
+set -e
+
+if [ "$#" -ne 1 ]; then
+    echo "Usage: $0 <release_tag>"
+    exit 1
+fi
+
+release_tag=$1
+latest_release=$(gh release list --json name,isLatest --jq '.[] | select(.isLatest)|.name')
+
+merge_base=$(git merge-base origin/main origin/next)
+pr_numbers=$(git log --pretty=format:"%s" $merge_base..origin/next | grep -oE 'Merge pull request #([0-9]+)' | grep -oE '[0-9]+')
+
+pre_release_tasks=""
+post_release_tasks=""
+
+for pr in $pr_numbers; do
+  echo "Processing PR #$pr"
+  pr_body=$(gh pr view "$pr" --json body -q '.body')
+  pre=$(echo "$pr_body" | sed -n '/Pre-Release:/,/Post-Release:/p' | grep '^[*-]' || true)
+  post=$(echo "$pr_body" | sed -n '/Post-Release:/,$p' | grep '^[*-]' || true)
+
+  if [ -n "$pre" ]; then
+    pre_release_tasks+="
+PR #$pr:
+$pre
+"
+  fi
+  if [ -n "$post" ]; then
+    post_release_tasks+="
+PR #$pr:
+$post
+"
+  fi
+done
+
+release_body="**Full Changelog**: https://github.com/nhsuk/manage-vaccinations-in-schools/compare/$latest_release...$release_tag
+"
+
+if [ -n "$pre_release_tasks" ]; then
+  release_body+="
+## Pre-Release Tasks
+${pre_release_tasks}
+"
+fi
+if [ -n "$post_release_tasks" ]; then
+  release_body+="
+## Post-Release Tasks
+${post_release_tasks}
+"
+fi
+
+echo "$release_body" > release_notes.md