Update Node.js version in GitHub Actions workflow from 18 to 20

Author: gavinmcfarland

.github/workflows/run-create-plugma.yml

@@ -18,7 +18,7 @@ jobs:
             - name: Set up Node.js
               uses: actions/setup-node@v3
               with:
-                  node-version: '18'
+                  node-version: '20'
 
             - name: Install dependencies
               run: |