build:remove build packages workflow (#4835)

.github/workflows/build-packages.yml

@@ -1,29 +0,0 @@
-name: Build packages
-
-on:
-  push:
-    branches:
-      - master
-  pull_request:
-
-jobs:
-  packages:
-    runs-on: ubuntu-latest
-
-    steps:
-      - uses: actions/checkout@v2
-      - name: Setup Node.js 14.x
-        uses: actions/setup-node@v2
-        with:
-          node-version: 14.x
-      - name: Install dependencies
-        run: |
-          yarn --frozen-lockfile
-          yarn --cwd src/packages/excalidraw
-          yarn --cwd src/packages/utils
-      - name: Build @excalidraw/excalidraw
-        run: |
-          yarn --cwd src/packages/excalidraw run pack
-      - name: Build @excalidraw/utils
-        run: |
-          yarn --cwd src/packages/utils run pack