perform periodic updates for v8.0-preview

Signed-off-by: Aolin <aolinz@outlook.com>

.github/workflows/sync_scheduler.yml

@@ -2,10 +2,8 @@ name: Sync docs on schedule
 
 on:
   workflow_dispatch:
-#  schedule:
-#    - cron: "0 0 */15 * *" # every 15 days
-#    - cron: "0 0 * * *" # every day at 00:00
-#    - cron: "0 */6 * * *" # every 6 hours
+  schedule:
+    - cron: "0 */6 * * *" # every 6 hours
 
 jobs:
   sync_scheduler:
@@ -20,24 +18,7 @@ jobs:
     - name: Checkout current repo
       uses: actions/checkout@v3
 
-    - name: Sync scaffold on schedule
-      if: github.event_name == 'schedule' && github.event.schedule == '0 0 */15 * *'
-      run: |
-        gh workflow run sync_scaffold.yml --ref ${{env.SCAFFOLD_BRANCH}}
-
-    - name: Sync preview branch on schedule
-      if: github.event_name == 'schedule' && github.event.schedule == '0 0 * * *'
-      run: |
-        gh workflow run sync_pr.yml --ref ${{env.PREVIEW_BRANCH}}
-
     - name: Sync preview branch (multiple PRs) on schedule
       if: github.event_name == 'schedule' && github.event.schedule == '0 */6 * * *'
       run: |
-        gh workflow run sync_mult_prs.yml --ref ${{env.MULT_PR_PREVIEW_BRANCH}}
-
-    - name: Sync multiple branches on workflow_dispatch
-      if: github.event_name == 'workflow_dispatch'
-      run: |
-        gh workflow run sync_scaffold.yml --ref ${{env.SCAFFOLD_BRANCH}}
-        gh workflow run sync_pr.yml --ref ${{env.PREVIEW_BRANCH}}
-        gh workflow run sync_mult_prs.yml --ref ${{env.MULT_PR_PREVIEW_BRANCH}}
+        gh workflow run sync_mult_prs.yml --ref v8.0-preview