fix: upgrade npm dependency to v8

BREAKING CHANGE: npm v8 dropped support for node v15, so it is no longer supported in this plugin. this should be low impact since node v15 is already EOL

Co-authored-by: Matt Travi <programmer@travi.org>

.github/workflows/test.yml

@@ -14,7 +14,8 @@ jobs:
       matrix:
         node-version:
           - 14.17
-          - 16
+          - 16.0.0
+          - 17
         os:
           - ubuntu-latest
     runs-on: "${{ matrix.os }}"
@@ -34,7 +35,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v2
         with:
-          node-version: 16
+          node-version: 'lts/*'
           cache: npm
       - run: npm ci
       - name: Ensure dependencies are compatible with the version of node