package/libxml2: bump version to 2.11.4

Release notes:
https://download.gnome.org/sources/libxml2/2.11/libxml2-2.11.0.news
https://download.gnome.org/sources/libxml2/2.11/libxml2-2.11.1.news
https://download.gnome.org/sources/libxml2/2.11/libxml2-2.11.2.news
https://download.gnome.org/sources/libxml2/2.11/libxml2-2.11.3.news
https://download.gnome.org/sources/libxml2/2.11/libxml2-2.11.4.news

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit dfe1ca7872a45bcdc825ff0900d7fd929097a635)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libxml2/libxml2.hash

@@ -1,4 +1,4 @@
-# From https://download.gnome.org/sources/libxml2/2.10/libxml2-2.10.4.sha256sum
-sha256  ed0c91c5845008f1936739e4eee2035531c1c94742c6541f44ee66d885948d45  libxml2-2.10.4.tar.xz
+# From https://download.gnome.org/sources/libxml2/2.11/libxml2-2.11.4.sha256sum
+sha256  737e1d7f8ab3f139729ca13a2494fd17bf30ddb4b7a427cf336252cab57f57f7  libxml2-2.11.4.tar.xz
 # License files, locally calculated
 sha256  c5c63674f8a83c4d2e385d96d1c670a03cb871ba2927755467017317878574bd  Copyright

package/libxml2/libxml2.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-LIBXML2_VERSION_MAJOR = 2.10
+LIBXML2_VERSION_MAJOR = 2.11
 LIBXML2_VERSION = $(LIBXML2_VERSION_MAJOR).4
 LIBXML2_SOURCE = libxml2-$(LIBXML2_VERSION).tar.xz
 LIBXML2_SITE = \