vala: update to version 0.56.0 (LTS version)

According, to the project website [1], we were not using long-term
version, but stable one. Let's use LTS version.

Changelog can be found on their GitLab [2].

[1] https://wiki.gnome.org/Projects/Vala
[2] https://gitlab.gnome.org/GNOME/vala/raw/0.56/NEWS

Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>
(cherry picked from commit 189f078a35)

lang/vala/Makefile

@@ -8,12 +8,12 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=vala
-PKG_VERSION:=0.54.8
+PKG_VERSION:=0.56.0
 PKG_RELEASE:=$(AUTORELEASE)
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
-PKG_SOURCE_URL:=@GNOME/vala/0.54
-PKG_HASH:=edfb3e79486a4bf48cebaea9291e57fc77da9322b6961e9549df6d973d04bc80
+PKG_SOURCE_URL:=@GNOME/vala/0.56
+PKG_HASH:=d92bd13c5630905eeb6a983dcb702204da9731460c2a6e4e39f867996f371040
 
 PKG_MAINTAINER:=
 PKG_LICENSE:=LGPL-2.1-or-later