Migrate docs workflows from preview-build to docs-actions (#5897)

Moves docs CI/CD from elastic/docs-builder to elastic/docs-actions.
Part of elastic/docs-eng-team#474

Co-authored-by: Mika Ayenson, PhD <Mikaayenson@users.noreply.github.com>

.github/workflows/docs-build.yml

@@ -1,23 +1,12 @@
 name: docs-build
-
 on:
+  pull_request:
+    types: [opened, synchronize, reopened]
   push:
-    branches:
-      - main
-  pull_request_target: ~
-
+    branches: [main]
+permissions:
+  contents: read
+  pull-requests: read
 jobs:
-  preview:
-    uses: elastic/docs-builder/.github/workflows/preview-build.yml@main
-    with:
-      continue-on-error: false
-      strict: true
-      path-pattern: |
-        docs/**
-        rules/**
-        rules_building_block/**
-    permissions:
-      deployments: write
-      id-token: write
-      contents: read
-      pull-requests: write
+  build:
+    uses: elastic/docs-actions/.github/workflows/docs-build.yml@v1