Update actions/checkout action to v4

Author: renovate[bot]

.github/workflows/npm-publish.yml

@@ -11,7 +11,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: actions/setup-node@v1
         with:
           node-version: 12
@@ -22,7 +22,7 @@ jobs:
     needs: build
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: actions/setup-node@v1
         with:
           node-version: 12
@@ -36,7 +36,7 @@ jobs:
     needs: build
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: actions/setup-node@v1
         with:
           node-version: 12