No need to publish if not on main. Just validate. (#8)

Split the tasks, and also update [setup-node](https://github.com/actions/setup-node).

.github/workflows/npm-renderer-out.yaml

@@ -6,23 +6,21 @@ permissions:
 on:
   push:
     branches: [ "main" ]
-  pull_request:
-    branches: [ "main" ]
 
 jobs:
   build:
     runs-on: ubuntu-latest
 
     strategy:
       matrix:
-        node-version: [18.x]
+        node-version: [20.x]
 
     steps:
     - name: Check out Repository
       uses: actions/checkout@v4
 
     - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v3
+      uses: actions/setup-node@v4
       with:
         node-version: ${{ matrix.node-version }}
 
@@ -33,7 +31,7 @@ jobs:
     - name: Upload the website
       uses: actions/upload-artifact@v4
       with:
-        name: test-artifact
+        name: offline-website
         path: out/renderer/
         if-no-files-found: error
         overwrite: true

.github/workflows/npm-validate-build.yaml

@@ -0,0 +1,27 @@
+name: Validate Web Build
+run-name: Ensure the website can be built.
+on:
+  pull_request:
+    branches: [ "main" ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [20.x]
+
+    steps:
+    - name: Check out Repository
+      uses: actions/checkout@v4
+
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v4
+      with:
+        node-version: ${{ matrix.node-version }}
+
+    - name: Installing the project dependencies
+      run: npm ci
+    - name: Building the project
+      run: npm run build