chore: use Node 20 for main tests (#200)

Author: MichaelDeBoey

.github/workflows/ci.yml

@@ -32,7 +32,7 @@ jobs:
             - name: ⎔ Setup Node
               uses: actions/setup-node@v3
               with:
-                  node-version: 18
+                  node-version: 20
 
             - name: 📥 Install dependencies
               run: npm install
@@ -57,16 +57,16 @@ jobs:
                     # On other platforms
                     - os: windows-latest
                       eslint: 8
-                      node: 18
+                      node: 20
                     - os: macos-latest
                       eslint: 8
-                      node: 18
+                      node: 20
                     # On old ESLint versions
                     - eslint: 7
-                      node: 18
+                      node: 20
                       os: ubuntu-latest
                     - eslint: 6
-                      node: 18
+                      node: 20
                       os: ubuntu-latest
                     # On the minimum supported ESLint/Node.js version
                     - eslint: 6.6.0
@@ -108,7 +108,7 @@ jobs:
             - name: ⎔ Setup node
               uses: actions/setup-node@v3
               with:
-                  node-version: 18
+                  node-version: 20
 
             - name: 📥 Install dependencies
               run: npm install