Revert previous change, SKIP had a versionadded elsewhere
diff --git a/Doc/lib/libdoctest.tex b/Doc/lib/libdoctest.tex
index a70135d..4c4f228 100644
--- a/Doc/lib/libdoctest.tex
+++ b/Doc/lib/libdoctest.tex
@@ -628,7 +628,6 @@
     The SKIP flag can also be used for temporarily "commenting out"
     examples.
 
-  \versionadded{2.5}
 \end{datadesc}
 
 \begin{datadesc}{COMPARISON_FLAGS}