Avoid pandas 2.1.0 due to timestampt bug

Pandas 2.1.0 DataFrame constructor bug causeing timestamps to have
inconsistent units (pandas-dev/pandas#55014).

Author: IzerOnadimQC

environment.yml

@@ -9,7 +9,7 @@ dependencies:
   # Currently dask and numpy==1.16.0 clash
   # TODO: add support for numpy>=1.23
   - numpy!=1.15.0,!=1.16.0
-  - pandas>=0.23.0,!=1.0.0
+  - pandas>=0.23.0,!=1.0.0,!=2.1.0
   - pyarrow>=0.17.1,!=1.0.0
   - simplejson
   - minimalkv>=1.4.2