Update actions/checkout action to v4

Dependency update (patch) :)

Author: renovate[bot]

.github/workflows/npm-publish.yml

@@ -12,7 +12,7 @@ jobs:
   publish-npm:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: actions/setup-node@v2
         with:
           node-version: 14