[ci] update node version

Author: Mc-Zen

.github/workflows/deploy.yml

@@ -19,7 +19,7 @@ jobs:
           submodules: true
       - uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 20
           cache: npm
 
       - name: Install typst

.github/workflows/test-deploy.yml

@@ -1,3 +1,4 @@
+
 name: Test deployment
 
 on:
@@ -21,7 +22,7 @@ jobs:
           submodules: true
       - uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 20
           cache: npm
 
       - name: Install typst