Upgrade the NodeJS version to 20 for GitHub Actions.

Author: yoichiro

.github/workflows/production.yaml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [18.x]
+        node-version: [20.x]
     steps:
       - name: Checkout Repository
         uses: actions/checkout@v2

.github/workflows/pullrequest.yaml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [18.x]
+        node-version: [20.x]
     steps:
       - name: Checkout Repository
         uses: actions/checkout@v2