build: run github actions on pull requests (#27786)

.github/workflows/ci-static-analysis.yml

@@ -0,0 +1,43 @@
+name: CI
+
+on: pull_request
+
+jobs:
+  tests:
+    name: Static analysis
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        python-version: ['3.8']
+        os: ['ubuntu-20.04']
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install system requirements
+        run: sudo apt update && sudo apt install -y libxmlsec1-dev
+
+      - name: Install pip
+        run: python -m pip install -r requirements/pip.txt
+
+      - name: Get pip cache dir
+        id: pip-cache-dir
+        run: echo "::set-output name=dir::$(pip cache dir)"
+
+      - name: Cache pip dependencies
+        id: cache-dependencies
+        uses: actions/cache@v2
+        with:
+          path: ${{ steps.pip-cache-dir.outputs.dir }}
+          key: ${{ runner.os }}-pip-${{ hashFiles('requirements/edx/development.txt') }}
+          restore-keys: ${{ runner.os }}-pip-
+
+      - name: Install python dependencies
+        run: pip install -r requirements/edx/development.txt
+
+      - name: Static code analysis
+        run: make check-types