CI: Update to actions/checkout@v3

No functional change, but we should keep this current.
diff --git a/.github/workflows/openssl-nodeprecated.yml b/.github/workflows/openssl-nodeprecated.yml
index e423f58..e7f7ffa 100644
--- a/.github/workflows/openssl-nodeprecated.yml
+++ b/.github/workflows/openssl-nodeprecated.yml
@@ -21,7 +21,7 @@
   test:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Install VTest
       run: |
         scripts/build-vtest.sh