Added check SLO label workflow (#1957)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Copilot <198982749+Copilot@users.noreply.github.com>
Co-authored-by: asmyasnikov <14202262+asmyasnikov@users.noreply.github.com>

Author: 3 people

.github/workflows/check-slo-label.yml

@@ -0,0 +1,16 @@
+name: Check SLO Label
+
+on:
+  pull_request:
+    types: [opened, reopened, synchronize, labeled, unlabeled]
+
+jobs:
+  check-slo-label:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Fail if SLO label is missing
+        if: "!contains(github.event.pull_request.labels.*.name, 'SLO')"
+        run: |
+          echo "PR must have the \"SLO\" label to proceed."
+          exit 1