try removing libxml2 include path

conda/bld.bat

@@ -30,8 +30,6 @@ cmake -G "Ninja" ^
  -D BUILD_CONVERT:BOOL=ON ^
  -D BUILD_IFCMAX:BOOL=OFF ^
  -D IFCXML_SUPPORT:BOOL=OFF ^
- -D LIBXML2_INCLUDE_DIR:FILEPATH="%LIBRARY_PREFIX%\include" ^
- -D LIBXML2_LIBRARIES:FILEPATH=%LIBXML2% ^
  -D BOOST_LIBRARYDIR:FILEPATH="%LIBRARY_PREFIX%\lib" ^
  -D BOOST_INCLUDEDIR:FILEPATH="%LIBRARY_PREFIX%\include" ^
  -D BOOST_USE_STATIC_LIBS:BOOL=OFF ^

conda/build.sh

@@ -36,7 +36,6 @@ cmake -G Ninja \
  -DBUILD_IFCPYTHON:BOOL=ON \
  -DBUILD_IFCGEOM:BOOL=ON \
  -DBUILD_GEOMSERVER:BOOL=OFF \
- -DIFCXML_SUPPORT:BOOL=OFF \
  -DBOOST_USE_STATIC_LIBS:BOOL=OFF \
  ./cmake