ci(verification-matrix): install latest corepack so latest npm signing key is available

Author: travi

.github/workflows/node-ci.yml

@@ -30,6 +30,7 @@ jobs:
           cache: npm
           node-version: ${{ matrix.node }}
       - run: npm clean-install
+      - run: npm install --global corepack@latest
       - run: corepack npm audit signatures
       - run: npm test
   verify: