BLD: correct checkout versioning

Author: Gerry Manoim

.github/workflows/release.yml

@@ -8,7 +8,7 @@ jobs:
     name: Build and publish Python 🐍 distributions 📦 to TestPyPI
     runs-on: ubuntu-18.04
     steps:
-    - uses: actions/checkout@2
+    - uses: actions/checkout@v2
       with:
         submodules: 'recursive'
     - name: Set up Python 3.8