ci: add separate workflow for prestable sync

Refs: #20359, #21069

Author: PavelEfarinov

.github/workflows/prestable_sync.yml

@@ -0,0 +1,38 @@
+name: Sync prestables
+on:
+  schedule:
+    - cron: "30 0 * * *"   # At 00:30 -- for PR creation
+  workflow_dispatch:
+concurrency:
+  group: ${{ github.workflow }}
+  cancel-in-progress: true
+env:
+  GH_TOKEN: ${{ secrets.YDBOT_TOKEN }}
+jobs:
+  create-pr:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - base_branch: prestable-25-2
+            head_branch: stable-25-1
+            label: sync-prestable
+          - base_branch: prestable-25-3
+            head_branch: main
+            label: sync-prestable
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          sparse-checkout: |
+            .github
+            ydb/ci/
+      - uses: ./.github/actions/rightlib_sync
+        with:
+          base_branch: ${{ matrix.base_branch }}
+          head_branch: ${{ matrix.head_branch }}
+          label: ${{ matrix.label }}
+          repository: ${{ github.repository }}
+          gh_personal_access_token: ${{ env.GH_TOKEN }}

.github/workflows/rightlib_sync.yml

@@ -11,19 +11,6 @@ env:
 jobs:
   create-pr:
     runs-on: ubuntu-latest
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - base_branch: prestable-25-2
-            head_branch: stable-25-1
-            label: sync-prestable
-          - base_branch: prestable-25-3
-            head_branch: main
-            label: sync-prestable
-          - base_branch: main
-            head_branch: rightlib
-            label: rightlib
     steps:
       - name: checkout
         uses: actions/checkout@v4
@@ -34,8 +21,8 @@ jobs:
             ydb/ci/
       - uses: ./.github/actions/rightlib_sync
         with:
-          base_branch: ${{ matrix.base_branch }}
-          head_branch: ${{ matrix.head_branch }}
-          label: ${{ matrix.label }}
+          base_branch: main
+          head_branch: rightlib
+          label: rightlib
           repository: ${{ github.repository }}
           gh_personal_access_token: ${{ env.GH_TOKEN }}