GitHub Actions: add check for empty commit message

There is no checking of proposed commit message presence.

PR authors may forget to include proposed commit message.

Adding a check using GitHub Actions will help remind and ensure
that authors don't miss out on filling in the commit message.

Let's add a job to the a new workflow, pr-message-reminder.yml
file to help automate checking and reminding of filling in the
proposed commit message for each PR.

This approach automates the process, without having to have
other users check and remind PR authors themselves. Adding the
new job to a new workflow will allow greater control of job triggers
while maintaining clean code.

.github/workflows/pr-message-reminder.yml

@@ -0,0 +1,39 @@
+name: PR Message Reminder
+on:
+  push:
+    branches:
+      - master
+    tags:
+      - 'v[0-9]+.[0-9]+.[0-9]+'
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+      - edited
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+    remind-pr-author:
+        if: github.event_name == 'pull_request'
+        runs-on: ubuntu-latest
+
+        steps:
+          - uses: actions/checkout@v3
+          - name: Extract Proposed Commit Message
+            run: |
+              python scripts/process_message.py "${TEXT_BODY}" > processed_body.txt
+              processed_body=$(cat processed_body.txt)
+              proposed_commit_message=$(echo "$processed_body" | awk '/\\*\\*Proposed commit message: \\\(wrap lines at 72 characters\\\)\\*\\*/,/\\*\\*Checklist:\\*\\*/' | tail -n +2 | head -n -3)
+              echo "Proposed commit message:"
+              echo "$proposed_commit_message"
+              if ! grep -q '[^[:space:]]' <<< "$proposed_commit_message"; then
+                echo "Please fill in the proposed commit message section in the pull request description."
+                exit 1
+              fi
+            env:
+              TEXT_BODY: ${{ github.event.pull_request.body }}
+

scripts/process_message.py

@@ -0,0 +1,15 @@
+import json
+import re
+import sys
+
+markdown_content = sys.argv[1]
+
+# Preprocessing the markdown content
+markdown_content = markdown_content.replace('`', '\\`')
+markdown_content = markdown_content.replace('(', '\\(').replace(')', '\\)')
+markdown_content = re.sub(r'<!--.*?-->', '', markdown_content, flags=re.DOTALL)  # Remove HTML comments
+
+print(markdown_content)
+
+
+