Create job to generate sdist

Signed-off-by: Jono Yang <jyang@nexb.com>

Author: JonoYang

.github/workflows/pypi-release.yml

@@ -19,8 +19,34 @@ on:
       - "v*.*.*"
 
 jobs:
-  build-pypi-distribs:
-    name: Build and upload wheels and sdist
+  build-pypi-distribs-sdist:
+    name: Build and upload sdist
+    runs-on: ubuntu-24.04
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+
+      - name: Install build, twine, pkginfo, and packaging
+        run: python -m pip install --user --upgrade build twine pkginfo packaging
+
+      - name: Build sdist
+        run: python -m build --sdist --outdir dist/
+
+      - name: Validate sdist for Pypi
+        run: python -m twine check dist/*
+
+      - name: Upload sdist
+        uses: actions/upload-artifact@v4
+        with:
+          name: pypi_archives-sdist
+          path: dist/*
+
+  build-pypi-distribs-wheels:
+    name: Build and upload wheels
     runs-on: ubuntu-24.04
 
     strategy:
@@ -56,10 +82,17 @@ jobs:
   create-gh-release:
     name: Create GH release
     needs:
-      - build-pypi-distribs
+      - build-pypi-distribs-sdist
+      - build-pypi-distribs-wheels
     runs-on: ubuntu-24.04
 
     steps:
+      - name: Download sdist
+        uses: actions/download-artifact@v4
+        with:
+          name: pypi_archives-sdist
+          path: dist
+
       - name: Download ubuntu-latest builds
         uses: actions/download-artifact@v4
         with: