Github workflow: Upgrade to Node JS 20 (Latest LTS)

Author: jamesst20

.github/workflows/build.yml

@@ -17,7 +17,7 @@ jobs:
       - name: Setup Node.js
         uses: actions/setup-node@v2
         with:
-          node-version: 16.15
+          node-version: 20
 
       - name: Cache node modules
         uses: actions/cache@v2

.github/workflows/tests.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Setup Node.js
         uses: actions/setup-node@v2
         with:
-          node-version: 16.15
+          node-version: 20
 
       - name: Cache node modules
         uses: actions/cache@v2