test: Ensure broken node 16.9.0 isn't used (#1028)

Author: eps1lon

.github/workflows/validate.yml

@@ -18,7 +18,8 @@ jobs:
       # Otherwise we would not know if the problem is tied to the Node.js version
       fail-fast: false
       matrix:
-        node: [12, 14, 16]
+        # TODO: relax `'16.9.1'` to `16` once GitHub has 16.9.1 cached. 16.9.0 is broken due to https://github.com/nodejs/node/issues/40030
+        node: [12, 14, '16.9.1']
     runs-on: ubuntu-latest
     steps:
       - name: 🛑 Cancel Previous Runs