Set pandas ceiling for 0.9.x releases

This patch isolates a change needed to get patch-releases atop 0.9.0 to
pass `make check`.  This patch alone will not pass `make check`; see the
following octopus merge for a commit that passes `make check`.

Signed-off-by: Alex Nelson <alexander.nelson@nist.gov>

Author: ajnelson-nist

setup.cfg

@@ -19,7 +19,7 @@ license_files =
 [options]
 include_package_data = true
 install_requires =
-    pandas
+    pandas < 2.1.0
     pyshacl
     rdflib >= 6.2.0
     requests