image: apk: dont fail on removing a package that doesnt exist

image: apk: dont fail on removing a package that doesnt exist

Currently, in case when a package in the device package list is marked with
the "-"" prefix meaning that its supposed to be removed for that device but
it was not actually previously built it will cause the APK to error out it
and thus image generation will also fail.

So, lets do what OPKG build step does and supress the error with the "-"
prefix in make.

Fixes: #17103
Fixes: d788ab376f85 ("build: add APK package build capabilities")
Link: https://github.com/openwrt/openwrt/pull/17106
Signed-off-by: Robert Marko <robimarko@gmail.com>