zabbix: zabbix-server-frontend: update dependency

Only show zabbix-server-frontend if the build dependency 'PACKEGE_php8' is
fulfilled. This means that 'zabbix-server-frotend' can only be selected if
PHP has also been enabled for building.

This change is needed to fix the following recursive dependency warning.

error: recursive dependency detected!
   symbol PACKAGE_php8 is selected by PACKAGE_zabbix-server-frontend
   symbol PACKAGE_zabbix-server-frontend depends on PHP8_DOM
   symbol PHP8_DOM depends on PACKAGE_php8
For a resolution refer to Documentation/kbuild/kconfig-language.rst

Signed-off-by: Florian Eckert <fe@dev.tdt.de>

admin/zabbix/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=zabbix
 PKG_VERSION:=7.0.21
-PKG_RELEASE:=2
+PKG_RELEASE:=3
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://cdn.zabbix.com/zabbix/sources/stable/$(basename $(PKG_VERSION))/ \
@@ -189,7 +189,7 @@ endef
 define Package/zabbix-server-frontend
   $(call Package/zabbix/Default)
   TITLE+= server-frontend
-  DEPENDS += +php8 \
+  DEPENDS += @PACKAGE_php8 \
     +php8-cgi \
     +php8-mod-gd \
     +php8-mod-bcmath \