update the CI to enforce the db change label on PR

.github/workflows/db-change.yml

@@ -0,0 +1,25 @@
+name: Check db change labels
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened, labeled, unlabeled]
+
+env:
+  GH_TOKEN: ${{ secrets.MEILI_BOT_GH_PAT }}
+
+jobs:
+  check-labels:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+      - name: Check db change labels
+        id: check_labels
+        run: |
+          LABELS=$(gh api -H "Accept: application/vnd.github.v3+json" /repos/meilisearch/meilisearch/pulls/${{ github.event.pull_request.number }}/labels -q .[].name)
+          if [[ ! "$LABELS" =~ "db change" && ! "$LABELS" =~ "no db change" ]]; then
+            echo "::error::Pull request must contain either the 'db change' or 'no db change' label."
+            exit 1
+          else
+            echo "The label is set"
+          fi

bors.toml

@@ -5,6 +5,7 @@ status = [
     'Run Clippy',
     'Run Rustfmt',
     'Run tests in debug',
+    'Check db change labels',
 ]
 pr_status = ['Milestone Check']
 # 3 hours timeout