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/systemctl/systemctl.c

@@ -25,6 +25,7 @@
 #include "signal-util.h"
 #include "stat-util.h"
 #include "string-table.h"
+#include "systemctl.h"
 #include "systemctl-add-dependency.h"
 #include "systemctl-cancel-job.h"
 #include "systemctl-clean-or-freeze.h"
@@ -61,7 +62,6 @@
 #include "systemctl-trivial-method.h"
 #include "systemctl-util.h"
 #include "systemctl-whoami.h"
-#include "systemctl.h"
 #include "terminal-util.h"
 #include "time-util.h"
 #include "user-util.h"