Publish portable Darling runtime patch snapshot and testing tools

.github/workflows/source-check.yml

@@ -0,0 +1,13 @@
+name: Source package checks
+on: [push, pull_request]
+permissions:
+  contents: read
+jobs:
+  validate:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+      - run: python scripts/validate.py