Test on non-ascii working directory in CI

.github/workflows/main.yml

@@ -6,9 +6,6 @@ on:
       - 'docs/**'
       - '.cirrus.yml'
       - '.github/workflows/docs.yml'
-    branches:
-      - master
-      - develop
   pull_request:
     paths-ignore:
       - 'docs/**'
@@ -27,21 +24,20 @@ jobs:
     runs-on: ${{ matrix.image }}
     strategy:
       matrix:
-        os: [Ubuntu, macOS, Windows]
+        os: [Windows]
         python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
         include:
-          - os: Ubuntu
-            image: ubuntu-22.04
           - os: Windows
             image: windows-2022
-          - os: macOS
-            image: macos-12
       fail-fast: false
     defaults:
       run:
         shell: bash
+        working-directory: ä
     steps:
       - uses: actions/checkout@v4
+        with:
+          path: ä
 
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4