GitHub workflows: run checker on Friday

.github/workflows/checker.yml

@@ -0,0 +1,31 @@
+name: "Checker"
+on:
+  schedule:
+    - cron: "0 4 * * 5"
+  workflow_dispatch:
+
+jobs:
+  checker:
+    name: Checker
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install Ubuntu packages
+        run: |
+          sudo ./utils/searxng.sh install packages
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+          architecture: 'x64'
+
+      - name: Install Python dependencies
+        run: |
+          make V=1 install
+
+      - name: Checker
+        run: |
+          make search.checker