pandas is not needed to run tests.

--- domdf_python_tools-3.9.0/tests/requirements.txt.orig
+++ domdf_python_tools-3.9.0/tests/requirements.txt
@@ -6,7 +6,6 @@
 flake8<5,>=3.8.4
 funcy>=1.16
 importlib-metadata>=3.6.0
-pandas>=1.0.0; implementation_name == "cpython" and python_version < "3.11"
 pytest>=6.0.0
 pytest-cov>=2.8.1
 pytest-randomly>=3.7.0