make openpyxl a standard requirement

Author: rwedge

pyproject.toml

@@ -31,6 +31,7 @@ dependencies = [
     "numpy>=1.24.0;python_version>='3.10' and python_version<'3.12'",
     "numpy>=1.26.0;python_version>='3.12' and python_version<'3.13'",
     "numpy>=2.1.0;python_version>='3.13'",
+    'openpyxl>=3.1.2',
     "pandas>=1.4.0;python_version<'3.11'",
     "pandas>=1.5.0;python_version>='3.11' and python_version<'3.12'",
     "pandas>=2.1.1;python_version>='3.12' and python_version<'3.13'",
@@ -78,8 +79,6 @@ test = [
     'jupyter>=1.0.0,<2',
     'tomli>=2.0.0,<3',
     'slack-sdk>=3.23,<4.0',
-    "openpyxl>=3.0.0; python_version<'3.9'",
-    "openpyxl>=3.1.2; python_version>='3.9'",
     'pydrive2>=1.4.0,<2.0.0'
 ]
 dev = [