fix(ci): remove npm cache and install steps — no dependencies

The repo has zero npm dependencies, so `cache: 'npm'` fails on missing
package-lock.json and `npm install` is a no-op.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: deanzaka

.github/workflows/ci.yml

@@ -19,10 +19,6 @@ jobs:
         uses: actions/setup-node@v4
         with:
           node-version: '22'
-          cache: 'npm'
-
-      - name: Install dependencies
-        run: npm install
 
       - name: Run CI checks
         run: npm run ci

.github/workflows/publish-bundle.yml

@@ -20,9 +20,6 @@ jobs:
         with:
           node-version: '22'
 
-      - name: Install dependencies
-        run: npm install
-
       - name: Validate
         run: npm run validate