GitHub Actions: Upgrade checkout and setup-python

https://github.com/actions/checkout/releases
https://github.com/actions/setup-python/releases

Author: cclauss

.github/workflows/main.yml

@@ -9,8 +9,8 @@ jobs:
     name: Run Canonical ABI Tests
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
-    - uses: actions/setup-python@v3
+    - uses: actions/checkout@v4
+    - uses: actions/setup-python@v5
       with:
-        python-version: '>= 3.10.0'
+        python-version: 3.x
     - run: python design/mvp/canonical-abi/run_tests.py