mkosi: Drop number prefixes from configuration files

We already removed these in some places, let's migrate the others as
well. There's no ordering required at all between these configuration
files so let's not bother with any numbered prefixes.

.packit.yml

@@ -19,7 +19,7 @@ actions:
   post-upstream-clone:
     # Use the Fedora Rawhide specfile
     - git clone https://src.fedoraproject.org/rpms/systemd .packit_rpm
-    - bash -c 'git -C .packit_rpm checkout "$(grep GIT_COMMIT= mkosi.conf.d/10-centos-fedora/mkosi.conf | cut -d= -f2)"'
+    - bash -c 'git -C .packit_rpm checkout "$(grep GIT_COMMIT= mkosi.conf.d/centos-fedora/mkosi.conf | cut -d= -f2)"'
     - bash -c 'echo "%bcond upstream 1" > .packit_rpm/systemd.spec.new'
     - bash -c 'echo "%define meson_extra_configure_options --werror" >> .packit_rpm/systemd.spec.new'
     - bash -c 'cat .packit_rpm/systemd.spec >> .packit_rpm/systemd.spec.new'

mkosi.conf.d/tools/mkosi.conf.d/ubuntu/mkosi.conf.d/non-x86.conf

@@ -7,4 +7,4 @@ Architecture=!x86
 ToolsTreeRelease=noble
 
 [Build]
-ToolsTreeSandboxTrees=%D/mkosi.conf.d/10-ubuntu/noble-backports-ports.sources:/etc/apt/sources.list.d/noble-backports-ports.sources
+ToolsTreeSandboxTrees=%D/mkosi.conf.d/ubuntu/noble-backports-ports.sources:/etc/apt/sources.list.d/noble-backports-ports.sources

mkosi.conf.d/tools/mkosi.conf.d/ubuntu/mkosi.conf.d/x86.conf

@@ -7,4 +7,4 @@ Architecture=|x86
 ToolsTreeRelease=noble
 
 [Build]
-ToolsTreeSandboxTrees=%D/mkosi.conf.d/10-ubuntu/noble-backports.sources:/etc/apt/sources.list.d/noble-backports.sources
+ToolsTreeSandboxTrees=%D/mkosi.conf.d/ubuntu/noble-backports.sources:/etc/apt/sources.list.d/noble-backports.sources