update node version to 20

Author: CppCXY

.github/workflows/build.yml

@@ -21,7 +21,7 @@ jobs:
     steps:
     - uses: actions/setup-node@v3
       with:
-        node-version: '16'
+        node-version: '20'
     - uses: actions/checkout@v3
       with:
         ref: refs/heads/master

.github/workflows/codestyle.yml

@@ -20,7 +20,7 @@ jobs:
     steps:
     - uses: actions/setup-node@v3
       with:
-        node-version: '16'
+        node-version: '20'
     - uses: actions/checkout@v3
     - name: install gcc 11
       if: startsWith(matrix.os, 'ubuntu')