Fix Windows Unicode encoding error in CI

- Remove checkmark emoji from Python test output message
- Fixes UnicodeEncodeError: 'charmap' codec can't encode character '\u2705'
- Windows console doesn't support Unicode emojis properly
- Keep plain text output for cross-platform compatibility

Author: Alexander Refsum Jensenius

.github/workflows/ci.yml

@@ -58,4 +58,4 @@ jobs:
 
     - name: Test basic import
       run: |
-        python -c "import musicalgestures; print('✅ MGT-python import successful on ${{ matrix.os }} Python ${{ matrix.python-version }}')"
+        python -c "import musicalgestures; print('MGT-python import successful on ${{ matrix.os }} Python ${{ matrix.python-version }}')"