ci: add node 20.x & use latest action dependencies (#267)

Author: erisu

.github/workflows/ci.yml

@@ -27,14 +27,14 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [18.x]
+        node-version: [18.x, 20.x]
         os: [ubuntu-latest, windows-latest, macos-latest]
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Use Node.js ${{ matrix.node-version }}
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
 
@@ -48,6 +48,6 @@ jobs:
         env:
           CI: true
 
-      - uses: codecov/codecov-action@v3
+      - uses: codecov/codecov-action@v4
         with:
           fail_ci_if_error: true