tree-wide: Sort includes

This was done by running a locally built clang-format with
https://github.com/llvm/llvm-project/pull/137617 and
https://github.com/llvm/llvm-project/pull/137840 applied on all .c
and .h files.

src/core/unit.c

@@ -21,8 +21,8 @@
 #include "cgroup-util.h"
 #include "chase.h"
 #include "core-varlink.h"
-#include "dbus-unit.h"
 #include "dbus.h"
+#include "dbus-unit.h"
 #include "dropin.h"
 #include "dynamic-user.h"
 #include "env-util.h"
@@ -60,8 +60,8 @@
 #include "terminal-util.h"
 #include "tmpfile-util.h"
 #include "umask-util.h"
-#include "unit-name.h"
 #include "unit.h"
+#include "unit-name.h"
 #include "user-util.h"
 #include "virt.h"
 #if BPF_FRAMEWORK