Add ruff to tests, adjust CI/CD runs

Author: vanous

.github/workflows/check-links.yaml

@@ -1,6 +1,6 @@
 name: Check links in markdown
 
-on: push
+on: [push, pull_request]
 
 jobs:
   test_links_in_readme:

.github/workflows/ruff.yml

@@ -0,0 +1,13 @@
+name: Check if code is formatted
+on: [ push, pull_request ]
+jobs:
+  ruff:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: astral-sh/ruff-action@v1
+        with:
+          args: --version
+      - uses: astral-sh/ruff-action@v1
+        with:
+          args: format --check

.github/workflows/run-tests.yaml

@@ -21,7 +21,9 @@ jobs:
           python-version: ${{ matrix.python-version }}
           allow-prereleases: true
       - name: Install dependencies
-        run: pip install pytest pytest-md pytest-emoji pytest-mypy
+        run: |
+          pip install pytest pytest-md pytest-emoji pytest-mypy
+          pip install multicast_expert 
       - uses: pavelzw/pytest-action@v2
         with:
           verbose: true