[libxml2] Remove outdated ChangeLog code

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 8eb0693746569ae5d8da85d2f113fdb141b4d695
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Mon Feb 14 01:01:23 2022 +0100

    Remove outdated ChangeLog code
    
    The ChangeLog is from pre-Git times.

 doc/ChangeLog.awk |  49 -----------------------
 doc/ChangeLog.xsl | 117 ------------------------------------------------------
 doc/Makefile.am   |   1 -
 3 files changed, 167 deletions(-)
---
diff --git a/doc/Makefile.am b/doc/Makefile.am
index deca2c03..473b549b 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -66,7 +66,6 @@ EXTRA_DIST = \
        APIfiles.html \
        APIfunctions.html \
        APIsymbols.html \
-       ChangeLog.xsl \
        DOM.gif \
        DOM.html \
        FAQ.html \