CI: Prevent large files from being added

.github/workflows/file-size.yml

@@ -0,0 +1,33 @@
+name: File Size Check
+
+on: [push, pull_request]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.10"]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Get changed files
+      id: changed-files
+      uses: tj-actions/changed-files@v18.4
+    - name: List all changed files
+      run: |
+        # MAXSIZE is 1 MB
+        MAXSIZE=1000000
+        for FILENAME in ${{ steps.changed-files.outputs.all_changed_files }}; do
+          FILESIZE=$(stat -c%s "$FILENAME")
+          echo "Size of $FILENAME = $FILESIZE bytes."
+          if (( FILESIZE > MAXSIZE)); then
+            echo "$FILENAME is too big. Only $MAXSIZE bytes allowed."
+            exit 1
+          fi
+        done