cleanup: use THD_STAGE_INFO, not thd_proc_info

and put master-slave.inc *last* in the series of includes

mysql-test/suite/rpl/t/rpl_parallel_sbm.test

 #
 #   Ensure that Seconds_Behind_Master works correctly on the parallel replica.
 #
---source include/master-slave.inc
 --source include/have_log_bin.inc
 --source include/have_debug.inc
+--source include/master-slave.inc
 
 --echo #
 --echo # MDEV-29639: Seconds_Behind_Master is incorrect for Delayed, Parallel Replicas

sql/rpl_rli.cc

@@ -44,8 +44,6 @@ rpl_slave_state *rpl_global_gtid_slave_state;
 /* Object used for MASTER_GTID_WAIT(). */
 gtid_waiting rpl_global_gtid_waiting;
 
-const char *const Relay_log_info::state_delaying_string = "Waiting until MASTER_DELAY seconds after master executed event";
-
 Relay_log_info::Relay_log_info(bool is_slave_recovery, const char* thread_name)
   :Slave_reporting_capability(thread_name),
    replicate_same_server_id(::replicate_same_server_id),

sql/rpl_rli.h

@@ -506,11 +506,6 @@ class Relay_log_info : public Slave_reporting_capability
     m_flags&= ~flag;
   }
 
-  /**
-    Text used in THD::proc_info when the slave SQL thread is delaying.
-  */
-  static const char *const state_delaying_string;
-
   bool flush();
 
   /**
@@ -533,7 +528,7 @@ class Relay_log_info : public Slave_reporting_capability
   {
     mysql_mutex_assert_owner(&data_lock);
     sql_delay_end= delay_end;
-    thd_proc_info(sql_driver_thd, state_delaying_string);
+    THD_STAGE_INFO(sql_driver_thd, stage_sql_thd_waiting_until_delay);
   }
 
   int32 get_sql_delay() { return sql_delay; }

sql/slave.cc

@@ -3324,7 +3324,7 @@ static bool send_show_master_info_data(THD *thd, Master_info *mi, bool full,
     // to ensure that we use the same value throughout this function.
     const char *slave_sql_running_state=
       mi->rli.sql_driver_thd ? mi->rli.sql_driver_thd->proc_info : "";
-    if (slave_sql_running_state == Relay_log_info::state_delaying_string)
+    if (slave_sql_running_state == stage_sql_thd_waiting_until_delay.m_name)
     {
       time_t t= my_time(0), sql_delay_end= mi->rli.get_sql_delay_end();
       protocol->store((uint32)(t < sql_delay_end ? sql_delay_end - t : 0));