docs: missing white papers section in RTD (acts-project#3067)

After acts-project#2797 the white papers were missing in the read the docs build. Thanks @beomki-yeo for noticing.
https://acts--3067.org.readthedocs.build/en/3067/white_papers/index.html

docs/conf.py

@@ -167,7 +167,7 @@
     extensions += ["lazy_autodoc"]
 
 
-if tags.has("white_papers"):
+if on_readthedocs or tags.has("white_papers"):
     import white_papers
 
     white_papers.render()