Update package version to 2.15.4

info.yml

@@ -1,7 +1,7 @@
 name: libxml2
 description: XML C parser and toolkit
-version: 2.15.3
-revision: 3
+version: 2.15.4
+revision: 1
 url: https://gitlab.gnome.org/GNOME/libxml2
 license: MIT
 maintainers:
@@ -24,4 +24,4 @@ downloads:
   - url: https://download.gnome.org/sources/libxml2/${BPM_PKG_VERSION%.*}/libxml2-${BPM_PKG_VERSION}.tar.xz
     extract_to: ${BPM_SOURCE}
     extract_strip_components: 1
-    checksum: 78262a6e7ac170d6528ebfe2efccdf220191a5af6a6cd61ea4a9a9a5042c7a07
+    checksum: 98087fd181d9070724f3fbc65c7377db03038eb92bd882374daff44940138821