bump deployment version to node 20

Author: Lenni009

.github/workflows/BuildAndDeploy.yml

@@ -7,21 +7,20 @@ on:
   push:
     branches: ['main']
 
+env:
+  node-version: 20
+
 jobs:
   build:
     environment: github-pages
     runs-on: ubuntu-latest
 
-    strategy:
-      matrix:
-        node-version: [19.x]
-
     steps:
       - uses: actions/checkout@v4
-      - name: Use Node.js ${{ matrix.node-version }}
+      - name: Use Node.js ${{ env.node-version }}
         uses: actions/setup-node@v4
         with:
-          node-version: ${{ matrix.node-version }}
+          node-version: ${{ env.node-version }}
           cache: 'npm'
 
       - name: Setup Secrets