Force to not use xindy while it's not supported

When using `xelatex`, Sphinx makes xindy to be used by default.

These changes here, force to not use xindy in that case either.

This will be supported at #5476

readthedocs/doc_builder/templates/doc_builder/conf.py.tmpl

@@ -149,6 +149,11 @@ language_user = globals().get('language', None)
 latex_engine_user = globals().get('latex_engine', None)
 latex_elements_user = globals().get('latex_elements', None)
 
+# Remove this once xindy gets installed in Docker image and XINDYOPS
+# env variable is supported
+# https://github.com/rtfd/readthedocs-docker-images/pull/98
+latex_use_xindy = False
+
 chinese = any([
     language_user in ('zh_CN', 'zh_TW'),
     project_language in ('zh_CN', 'zh_TW'),
@@ -162,16 +167,10 @@ japanese = any([
 if chinese:
     latex_engine = latex_engine_user or 'xelatex'
 
-    # Remove this once xindy gets installed in Docker image and XINDYOPS
-    # env variable is supported
-    # https://github.com/rtfd/readthedocs-docker-images/pull/98
-    latex_use_xindy = False
-
     latex_elements_rtd = {
         'preamble': '\\usepackage[UTF8]{ctex}\n',
     }
     latex_elements = latex_elements_user or latex_elements_rtd
 elif japanese:
     latex_engine = latex_engine_user or 'platex'
-    latex_use_xindy = False
 {% endif %}