ci: upgrade to Node.js 24 compatible action versions

.github/workflows/validate.yml

@@ -10,9 +10,9 @@ jobs:
   validate:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: "3.11"