relax requirements for pandas

.github/workflows/pythonpackage.yml

@@ -28,7 +28,7 @@ jobs:
     - name: Install additional dependencies
       run: |
         python -m pip install --upgrade pip cryptography
-        pip install wheel numpy Cython "pandas!=1.3.0"
+        pip install wheel numpy Cython
         pip install biom-format
     - name: Install MICOM
       run: pip install -e .