bpo-40439: Update broken link in lexical analysis docs (GH-20184)


Automerge-Triggered-By: @csabella
(cherry picked from commit af23f0d3cf19343512e6ca1fe1d46a5dbe425719)

Co-authored-by: Matteo Bertucci <matteobertucci2004@gmail.com>
diff --git a/Doc/reference/lexical_analysis.rst b/Doc/reference/lexical_analysis.rst
index 844bd7c..d0e7fde 100644
--- a/Doc/reference/lexical_analysis.rst
+++ b/Doc/reference/lexical_analysis.rst
@@ -325,7 +325,7 @@
 
 A non-normative HTML file listing all valid identifier characters for Unicode
 4.1 can be found at
-https://www.dcl.hpi.uni-potsdam.de/home/loewis/table-3131.html.
+https://www.unicode.org/Public/13.0.0/ucd/DerivedCoreProperties.txt
 
 
 .. _keywords: