Remove rebuild-search-index.yml

This is no longer needed because a hosted crawler is used

.github/workflows/rebuild-search-index.yml

@@ -1,20 +0,0 @@
-name: Rebuild Search Index
-on:
-  workflow_dispatch:
-permissions:
-  actions: write
-jobs:
-  build:
-    if: github.repository_owner == 'spring-projects'
-    runs-on: ubuntu-latest
-    steps:
-    - name: Checkout
-      uses: actions/checkout@v3
-      with:
-        ref: docs-build
-        fetch-depth: 1
-    - name: Dispatch
-      env:
-        GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-      run: gh workflow run rebuild-search-index.yml -r $(git rev-parse --abbrev-ref HEAD)
-