chore: update GitHub workflow node version and define node version in package.json (#650)

Author: garrett-green

.github/workflows/config.yml

@@ -9,7 +9,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 20
       - run: |
           npm install --legacy-peer-deps
       - run: |
@@ -19,4 +19,4 @@ jobs:
       - uses: actions/upload-artifact@v4
         with:
           name: code-coverage-report
-          path: reports
+          path: reports

package-lock.json

@@ -74,5 +74,8 @@
     "*.js": [
       "eslint"
     ]
+  },
+  "engines": {
+    "node": ">=20"
   }
 }