Update Node.js version to 18.x for sharp compatibility

- Update from Node.js 16.x to 18.x to meet sharp@0.34.3 requirements
- Fixes deployment error: sharp requires Node.js ^18.17.0 || ^20.3.0 || >=21.0.0

Author: codejaeger

.github/workflows/main.yml

@@ -16,7 +16,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [ 16.x ]
+        node-version: [ 18.x ]
 
     steps:
       - uses: actions/checkout@v4