chore(scripts): use ssh private key for git sync (#7224)

Author: trivikr

.github/workflows/git-sync.yml

@@ -12,14 +12,13 @@ jobs:
     steps:
       - name: git-sync
         env:
-          git_sync_source_repo: ${{ secrets.GIT_SYNC_SOURCE_REPO }}
           git_sync_destination_repo: ${{ secrets.GIT_SYNC_DESTINATION_REPO }}
-        if: env.git_sync_source_repo && env.git_sync_destination_repo
+          git_sync_ssh_private_key: ${{ secrets.GIT_SYNC_SSH_PRIVATE_KEY }}
+        if: env.git_sync_destination_repo && env.git_sync_ssh_private_key
         uses: wei/git-sync@v3
         with:
-          source_repo: ${{ secrets.GIT_SYNC_SOURCE_REPO }}
+          source_repo: "[email protected]:aws/aws-sdk-js-v3.git"
           source_branch: "main"
           destination_repo: ${{ secrets.GIT_SYNC_DESTINATION_REPO }} 
           destination_branch: "main"
-          source_ssh_private_key: ${{ secrets.GIT_SYNC_SOURCE_SSH_PRIVATE_KEY }}
-          destination_ssh_private_key:  ${{ secrets.GIT_SYNC_DESTINATION_SSH_PRIVATE_KEY }}
+          ssh_private_key: ${{ secrets.GIT_SYNC_SSH_PRIVATE_KEY }}