mkosi: Merge base and system images

The only reason to have these split up is to be able to build extension
images that use the base image as a base tree and install extra packages.
Until we have such a use case, let's merge the base and system images to
simplify things a bit.

We keep the mkosi.images/ directory to not cause too many conflicts with
the integration tests PR.

mkosi.images/base/mkosi.conf

@@ -1,55 +0,0 @@
-# SPDX-License-Identifier: LGPL-2.1-or-later
-
-[Output]
-Format=directory
-
-[Content]
-Autologin=yes
-# Make sure we build the default initrd as part of the base image as it will have access to the systemd and
-# udev rpms which are built by the build scripts that are part of the base image.
-Bootable=yes
-# we want to build the UKI as part of the system image so make sure none are built here.
-Bootloader=none
-CleanPackageMetadata=no
-
-Packages=
-        acl
-        bash-completion
-        coreutils
-        diffutils
-        dnsmasq
-        dosfstools
-        e2fsprogs
-        findutils
-        gcc # Sanitizer libraries
-        gdb
-        git
-        grep
-        gzip
-        jq
-        kbd
-        kexec-tools
-        kmod
-        less
-        man
-        mtools
-        nano
-        nftables
-        openssl
-        python3
-        qrencode
-        rsync
-        sed
-        socat
-        strace
-        systemd
-        tar
-        tmux
-        tree
-        udev
-        util-linux
-        valgrind
-        wireguard-tools
-        xfsprogs
-        zsh
-        zstd

mkosi.images/base/mkosi.conf.d/10-centos/mkosi.conf

@@ -1,12 +0,0 @@
-# SPDX-License-Identifier: LGPL-2.1-or-later
-
-[Match]
-Distribution=centos
-
-[Content]
-Environment=
-        PKG_SUBDIR="centos"
-
-Packages=
-        kernel-modules # For squashfs support
-        rpmautospec-rpm-macros

mkosi.images/system/mkosi.conf

@@ -1,17 +1,51 @@
 # SPDX-License-Identifier: LGPL-2.1-or-later
 
-[Config]
-Dependencies=base
-
-[Distribution]
-CacheOnly=metadata
-
 [Output]
 @Format=directory
 
 [Content]
-BaseTrees=%O/base
-Initrds=%O/base.initrd
+Autologin=yes
+Packages=
+        acl
+        bash-completion
+        coreutils
+        diffutils
+        dnsmasq
+        dosfstools
+        e2fsprogs
+        findutils
+        gcc # Sanitizer libraries
+        gdb
+        git
+        grep
+        gzip
+        jq
+        kbd
+        kexec-tools
+        kmod
+        less
+        man
+        mtools
+        nano
+        nftables
+        openssl
+        python3
+        qrencode
+        rsync
+        sed
+        socat
+        strace
+        systemd
+        tar
+        tmux
+        tree
+        udev
+        util-linux
+        valgrind
+        wireguard-tools
+        xfsprogs
+        zsh
+        zstd
 
 [Validation]
 @SecureBoot=yes

mkosi.images/system/mkosi.conf.d/10-centos/mkosi.conf

@@ -2,3 +2,11 @@
 
 [Match]
 Distribution=centos
+
+[Content]
+Environment=
+        PKG_SUBDIR="centos"
+
+Packages=
+        kernel-modules # For squashfs support
+        rpmautospec-rpm-macros