Remove github workflows to allow push without workflow scope

.github/workflows/ci.yml

-name: CI
-
-on:
-  push:
-    branches: [main]
-  pull_request:
-    branches: [main]
-
-jobs:
-  test:
-    name: Test & build
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-
-      - uses: actions/setup-node@v4
-        with:
-          node-version: '20'
-          cache: 'npm'
-
-      - name: Install dependencies
-        run: npm install
-
-      - name: Run server tests
-        run: npm test -w server
-
-      - name: Build server
-        run: npm run build -w server
-
-      - name: Build client
-        run: npm run build -w client