Remove optional test dependencies we do not have packaged yet.

--- pyfakefs-5.4.0/extra_requirements.txt.orig
+++ pyfakefs-5.4.0/extra_requirements.txt
@@ -8,13 +8,3 @@
 # Older versions might work ok, the versions chosen here are just the latest
 # available at the time of writing.
 pathlib2>=2.3.2
-scandir>=1.8
-
-# pandas + xlrd are used to test pandas-specific patches to allow
-# pyfakefs to work with pandas
-# we use the latest version to see any problems with new versions
-pandas==1.3.5; python_version == '3.7' # pyup: ignore
-pandas==2.0.3; python_version == '3.8' # pyup: ignore
-pandas==2.2.1; python_version > '3.8'
-xlrd==2.0.1
-openpyxl==3.1.2