Switch ydb-slo-action to main branch in slo-reports

Author: kprokopenko

.github/workflows/slo-report.yml

@@ -16,7 +16,7 @@ jobs:
     if: github.event.workflow_run.conclusion == 'success'
     steps:
       - name: Publish YDB SLO Report
-        uses: ydb-platform/ydb-slo-action/report@charts
+        uses: ydb-platform/ydb-slo-action/report@main
         with:         
           github_run_id: ${{ github.event.workflow_run.id }}
           github_token: ${{ secrets.GITHUB_TOKEN }}