Remove explicit npm 7 in GHA

Author: rolodato

.github/workflows/pull_request.yaml

@@ -34,7 +34,6 @@ jobs:
           restore-keys: |
             npm-${{ hashFiles('package-lock.json') }}
             npm-
-      - run: npm i -g [email protected]
       - run: npm install
       - run: npm test
         env: