basic/linux: import ioprio.h from kernel 6.14-rc4

This also fixes the maximum allowed ioprio class: 8 -> 7

src/core/dbus-execute.c

@@ -22,12 +22,11 @@
 #include "fileio.h"
 #include "hexdecoct.h"
 #include "hostname-util.h"
-#include "iovec-util.h"
 #include "ioprio-util.h"
+#include "iovec-util.h"
 #include "journal-file.h"
 #include "load-fragment.h"
 #include "memstream-util.h"
-#include "missing_ioprio.h"
 #include "mountpoint-util.h"
 #include "namespace.h"
 #include "parse-util.h"

src/core/exec-invoke.c

@@ -37,10 +37,10 @@
 #include "hexdecoct.h"
 #include "hostname-setup.h"
 #include "io-util.h"
+#include "ioprio-util.h"
 #include "iovec-util.h"
 #include "journal-send.h"
 #include "memfd-util.h"
-#include "missing_ioprio.h"
 #include "missing_prctl.h"
 #include "missing_sched.h"
 #include "missing_securebits.h"

src/core/load-fragment.c

@@ -41,14 +41,13 @@
 #include "fstab-util.h"
 #include "hexdecoct.h"
 #include "hostname-util.h"
-#include "iovec-util.h"
 #include "ioprio-util.h"
+#include "iovec-util.h"
 #include "ip-protocol-list.h"
 #include "journal-file.h"
 #include "limits-util.h"
 #include "load-fragment.h"
 #include "log.h"
-#include "missing_ioprio.h"
 #include "mountpoint-util.h"
 #include "nulstr-util.h"
 #include "open-file.h"