chore: Remove keyboard experimentation CI (#9609)

.github/workflows/keyboard_plugin_test.yml

@@ -1,66 +0,0 @@
-# Workflow for running the keyboard navigation plugin's automated tests.
-
-name: Keyboard Navigation Automated Tests
-
-on:
-  workflow_dispatch:
-  pull_request:
-  push:
-    branches:
-      - main
-
-permissions:
-  contents: read
-
-jobs:
-  webdriverio_tests:
-    name: WebdriverIO tests
-    timeout-minutes: 10
-    runs-on: ${{ matrix.os }}
-
-    strategy:
-      fail-fast: false
-      matrix:
-        os: [ubuntu-latest]
-
-    steps:
-      - name: Checkout core Blockly
-        uses: actions/checkout@v5
-        with:
-          path: core-blockly
-
-      - name: Checkout keyboard navigation plugin
-        uses: actions/checkout@v5
-        with:
-          repository: 'google/blockly-keyboard-experimentation'
-          ref: 'main'
-          path: blockly-keyboard-experimentation
-
-      - name: Use Node.js 20.x
-        uses: actions/setup-node@v5
-        with:
-          node-version: 20.x
-
-      - name: NPM install
-        run: |
-          cd core-blockly
-          npm install
-          cd ..
-          cd blockly-keyboard-experimentation
-          npm install
-          cd ..
-
-      - name: Link latest core main with plugin
-        run: |
-          cd core-blockly/packages/blockly
-          npm run package
-          cd dist
-          npm link
-          cd ../../../../blockly-keyboard-experimentation
-          npm link blockly
-          cd ..
-
-      - name: Run keyboard navigation plugin tests
-        run: |
-          cd blockly-keyboard-experimentation
-          npm run test