Remove setup-node from CI jobs — runner has Node pre-installed

setup-node@v4 was downloading Node 20 from GitHub (~5 min) instead of
using the runner's pre-installed copy. The Forgejo runner also has no
cache service backend (ETIMEDOUT on save/restore), so the cache: npm
integration provided no benefit and only added overhead.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.forgejo/workflows/deploy.yml

@@ -35,12 +35,6 @@ jobs:
             - name: ⬇️ Checkout repo
               uses: https://github.com/actions/checkout@v4
 
-            - name: ⬆️ Setup Node
-              uses: https://github.com/actions/setup-node@v4
-              with:
-                  node-version: '20'
-                  cache: 'npm'
-
             - name: 📥 Install dependencies
               run: npm ci
 
@@ -58,12 +52,6 @@ jobs:
             - name: ⬇️ Checkout repo
               uses: https://github.com/actions/checkout@v4
 
-            - name: ⬆️ Setup Node
-              uses: https://github.com/actions/setup-node@v4
-              with:
-                  node-version: '20'
-                  cache: 'npm'
-
             - name: 📥 Install dependencies
               run: npm ci
 
@@ -78,12 +66,6 @@ jobs:
             - name: ⬇️ Checkout repo
               uses: https://github.com/actions/checkout@v4
 
-            - name: ⬆️ Setup Node
-              uses: https://github.com/actions/setup-node@v4
-              with:
-                  node-version: '20'
-                  cache: 'npm'
-
             - name: 📥 Install dependencies
               run: npm ci