Update to upstream 2.6 tarball

- Update to upstream 2.6 tarball
- Add xxhash-devel as BuildRequire

Signed-off-by: Dodji Seketeli <dodji@redhat.com>

libabigail.spec

@@ -2,7 +2,7 @@
 %global tarball_name %{name}-%{version}
 
 Name: libabigail
-Version: 2.5
+Version: 2.6
 Release: 1%{?dist}
 Summary: Set of ABI analysis tools
 
@@ -17,6 +17,7 @@ BuildRequires: gcc-c++
 BuildRequires: libtool
 BuildRequires: elfutils-devel
 BuildRequires: libxml2-devel
+BuildRequires: xxhash-devel
 BuildRequires: doxygen
 BuildRequires: python3-sphinx
 BuildRequires: texinfo
@@ -162,6 +163,10 @@ fi
 %endif
 
 %changelog
+* Fri Nov 1 2024 Dodji Seketeli <dodji@redhat.com> - 2.6-1
+- Update to upstream 2.6 tarball
+- Add xxhash-devel as BuildRequires
+
 * Thu Apr 18 2024 Dodji Seketeli <dodji@redhat.com> - 2.5-1
 - Update to upstream 2.5 tarball
 - Drop patches