Need to fix all <scheme_name>_namelist.xml or CIME entry_id_pg.xsd to include input_pathname

[jimmielin]

Currently all scheme namelists have the same copy-pasted block describing the namelist XML, however this block

     input_pathname
          Only include this attribute to indicate that the variable
          contains the pathname of an input dataset that resides in the
          CESM inputdata directory tree.  Note that the variables
          containing the names of restart files that are used in branch
          runs don't reside in the inputdata tree and should not be given
          this attribute.

is incorrect.

case.build validates the scheme namelist XMLs against

/usr/bin/xmllint --noout --schema CAM-SIMA/cime/CIME/ParamGen/xml_schema/entry_id_pg.xsd

which does not define input_pathname so including one will actually error out

..._namelist.xml:9: element input_pathname: Schemas validity error : Element 'input_pathname': This element is not expected. Expected is one of ( desc, category, valid_values, group, values, standard_name, long_name, units, kind ).
..._namelist.xml fails to validate

Either all the scheme namelist.xml files need to be fixed to remove this block of text or entry_id_pg.xsd should be amended to add input_pathname