mkosi: Prevent busybox from getting pulled into opensuse images

OpenSUSE's busybox has a bunch of Provides for basic tools that cause
it to get pulled into images unless the corresponding tool is explicitly
installed so let's add explicit tools to make sure we don't get busybox.

mkosi.images/build/mkosi.conf.d/opensuse/mkosi.conf

@@ -11,8 +11,13 @@ Environment=
         PKG_SUBDIR=opensuse
 
 Packages=
-        gcc-c++
+        diffutils
         erofs-utils
+        gcc-c++
         git-core
+        grep
+        gzip
         patterns-base-minimal_base
         rpm-build
+        sed
+        xz

mkosi.images/exitrd/mkosi.conf.d/10-opensuse.conf

@@ -5,7 +5,11 @@ Distribution=opensuse
 
 [Content]
 Packages=
+        diffutils
+        grep
         patterns-base-minimal_base
+        sed
+        xz
 
 VolatilePackages=
         libsystemd0

mkosi.images/minimal-base/mkosi.conf.d/10-opensuse.conf

@@ -5,10 +5,14 @@ Distribution=opensuse
 
 [Content]
 Packages=
+        diffutils
+        grep
         hostname
         iproute2
         ncat
         patterns-base-minimal_base
+        sed
+        xz
 
 VolatilePackages=
         libsystemd0