Replace verb 'stage' with 'load' in schedules

"Staging table" will be the only valid use of 'stage' from now on.

src/test/regress/multi_fdw_schedule

@@ -20,6 +20,7 @@ test: multi_tpch_query1 multi_tpch_query3 multi_tpch_query6 multi_tpch_query10
 test: multi_tpch_query12 multi_tpch_query14 multi_tpch_query19
 
 # ----------
-# multi_fdw_large_shardid stages more shards into lineitem, and must come last
+# multi_fdw_large_shardid loads more lineitem data using high shard identifiers, and must
+# come last
 # ----------
 test: multi_fdw_large_shardid

src/test/regress/multi_schedule

@@ -55,7 +55,7 @@ test: multi_tpch_query12 multi_tpch_query14 multi_tpch_query19
 test: multi_tpch_query7 multi_tpch_query7_nested
 
 # ----------
-# Parallel tests to check our join order planning logic. Note that we stage data
+# Parallel tests to check our join order planning logic. Note that we load data
 # below; and therefore these tests should come after the execution tests.
 # ----------
 test: multi_join_order_tpch_small multi_join_order_additional
@@ -63,16 +63,16 @@ test: multi_stage_more_data
 test: multi_join_order_tpch_large
 
 # ----------
-# Tests for large-table join planning and execution.
+# Tests for large-table join planning and execution. Be careful when creating
-# Be careful when staging new data before these tests, as they
+# new shards before these tests, as they expect specific shard identifiers in
-# expect specific shard identifiers in the output.
+# the output.
 # ----------
 test: multi_large_table_join_planning
 test: multi_large_table_pruning
 test: multi_large_table_task_assignment
 
 # ----------
-# Tests to check our large record staging and shard deletion behavior
+# Tests to check our large record loading and shard deletion behavior
 # ----------
 test: multi_stage_large_records
 test: multi_master_delete_protocol
@@ -85,7 +85,7 @@ test: multi_index_statements
 test: multi_alter_table_statements
 
 # ----------
-# multi_create_schema tests creation, staging and querying of a table in a new
+# multi_create_schema tests creation, loading, and querying of a table in a new
 # schema (namespace).
 # ----------
 test: multi_create_schema
@@ -97,13 +97,13 @@ test: multi_create_schema
 test: multi_utility_warnings
 
 # ---------
-# multi_append_table_to_shard stages shards in a way that forces
+# multi_append_table_to_shard loads data to create shards in a way that forces
 # shard caching.
 # ---------
 test: multi_append_table_to_shard
 
 # ---------
-# multi_outer_join stages shards to create different mappings for outer joins
+# multi_outer_join loads data to create shards to test outer join mappings
 # ---------
 test: multi_outer_join
 
@@ -141,7 +141,7 @@ test: multi_copy
 test: multi_router_planner
 
 # ----------
-# multi_large_shardid stages more shards into lineitem
+# multi_large_shardid loads more lineitem data using high shard identifiers
 # ----------
 test: multi_large_shardid
 

src/test/regress/multi_task_tracker_extra_schedule

@@ -48,7 +48,7 @@ test: multi_tpch_query12 multi_tpch_query14 multi_tpch_query19
 test: multi_tpch_query7 multi_tpch_query7_nested
 
 # ----------
-# Parallel tests to check our join order planning logic. Note that we stage data
+# Parallel tests to check our join order planning logic. Note that we load data
 # below; and therefore these tests should come after the execution tests.
 # ----------
 test: multi_join_order_tpch_small multi_join_order_additional
@@ -56,20 +56,20 @@ test: multi_stage_more_data
 test: multi_join_order_tpch_large
 
 # ----------
-# Tests to check our large record staging and shard deletion behavior
+# Tests to check our large record loading and shard deletion behavior
 # ----------
 test: multi_stage_large_records
 test: multi_master_delete_protocol
 test: multi_shard_modify
 
 # ----------
-# multi_create_schema tests creation, staging and querying of a table in a new
+# multi_create_schema tests creation, loading, and querying of a table in a new
 # schema (namespace).
 # ----------
 test: multi_create_schema
 
 # ---------
-# multi_outer_join stages shards to create different mappings for outer joins
+# multi_outer_join loads data to create shards to test outer join mappings
 # ---------
 test: multi_outer_join
 
@@ -99,7 +99,7 @@ test: multi_data_types
 test: multi_copy
 
 # ----------
-# multi_large_shardid stages more shards into lineitem
+# multi_large_shardid loads more lineitem data using high shard identifiers
 # ----------
 test: multi_large_shardid