Move x-modulus-hash exchange to rabbit

Move the x-modulus-hash exchange type from rabbitmq_sharding to rabbit
since this exchange type is useful even without the sharding plugin.

(cherry picked from commit 1229705)

Author: ansd

deps/rabbit/Makefile

@@ -271,7 +271,7 @@ PARALLEL_CT_SET_4_D = per_user_connection_channel_tracking product_info queue_ty
 PARALLEL_CT_SET_5_A = rabbit_direct_reply_to_prop rabbit_quorum_queue_prop direct_reply_to_amqpl direct_reply_to_amqp classic_queue
 PARALLEL_CT_SET_5_B = feature_flags_v2 backing_queue transactions
 PARALLEL_CT_SET_5_C = cluster_upgrade maintenance_mode
-PARALLEL_CT_SET_5_D = rabbit_fifo_dlx_integration publisher_confirms_parallel
+PARALLEL_CT_SET_5_D = rabbit_fifo_dlx_integration publisher_confirms_parallel rabbit_exchange_type_modulus_hash
 
 PARALLEL_CT_SET_1 = $(sort $(PARALLEL_CT_SET_1_A) $(PARALLEL_CT_SET_1_B) $(PARALLEL_CT_SET_1_C) $(PARALLEL_CT_SET_1_D))
 PARALLEL_CT_SET_2 = $(sort $(PARALLEL_CT_SET_2_A) $(PARALLEL_CT_SET_2_B) $(PARALLEL_CT_SET_2_C) $(PARALLEL_CT_SET_2_D))

…_sharding_exchange_type_modulus_hash.erl …rc/rabbit_exchange_type_modulus_hash.erldeps/rabbitmq_sharding/src/rabbit_sharding_exchange_type_modulus_hash.erl renamed to deps/rabbit/src/rabbit_exchange_type_modulus_hash.erl deps/rabbitmq_sharding/src/rabbit_sharding_exchange_type_modulus_hash.erl renamed to deps/rabbit/src/rabbit_exchange_type_modulus_hash.erl

@@ -5,12 +5,12 @@
 %% Copyright (c) 2007-2026 Broadcom. All Rights Reserved. The term “Broadcom” refers to Broadcom Inc. and/or its subsidiaries. All rights reserved.
 %%
 
--module(rabbit_sharding_exchange_type_modulus_hash).
-
--include_lib("rabbit_common/include/rabbit.hrl").
+-module(rabbit_exchange_type_modulus_hash).
 
 -behaviour(rabbit_exchange_type).
 
+-include_lib("rabbit_common/include/rabbit.hrl").
+
 -export([description/0,
          route/3,
          serialise_events/0,
@@ -25,13 +25,12 @@
          remove_bindings/3,
          assert_args_equivalence/2]).
 
--rabbit_boot_step(
-   {rabbit_sharding_exchange_type_modulus_hash_registry,
-    [{description, "exchange type x-modulus-hash: registry"},
-     {mfa, {rabbit_registry, register, [exchange, <<"x-modulus-hash">>, ?MODULE]}},
-     {cleanup, {rabbit_registry, unregister, [exchange, <<"x-modulus-hash">>]}},
-     {requires, rabbit_registry},
-     {enables, kernel_ready}]}).
+-rabbit_boot_step({?MODULE,
+                   [{description, "exchange type x-modulus-hash"},
+                    {mfa, {rabbit_registry, register,
+                           [exchange, <<"x-modulus-hash">>, ?MODULE]}},
+                    {requires, rabbit_registry},
+                    {enables, kernel_ready}]}).
 
 %% 2^27
 -define(PHASH2_RANGE, 134217728).

…ding/test/rabbit_hash_exchange_SUITE.erl …bit_exchange_type_modulus_hash_SUITE.erldeps/rabbitmq_sharding/test/rabbit_hash_exchange_SUITE.erl renamed to deps/rabbit/test/rabbit_exchange_type_modulus_hash_SUITE.erl deps/rabbitmq_sharding/test/rabbit_hash_exchange_SUITE.erl renamed to deps/rabbit/test/rabbit_exchange_type_modulus_hash_SUITE.erl

@@ -4,7 +4,7 @@
 %%
 %% Copyright (c) 2007-2026 Broadcom. All Rights Reserved. The term “Broadcom” refers to Broadcom Inc. and/or its subsidiaries. All rights reserved.
 %%
--module(rabbit_hash_exchange_SUITE).
+-module(rabbit_exchange_type_modulus_hash_SUITE).
 
 -compile(export_all).
 

deps/rabbitmq_sharding/README.md

@@ -48,16 +48,10 @@ Do not use this plugin with quorum queues. Avoid classic mirrored queues in gene
 
 ## Messages Distribution Between Shards (Partitioning)
 
-The exchanges that ship by default with RabbitMQ work in an "all or
-nothing" fashion, i.e: if a routing key matches a set of queues bound
-to the exchange, then RabbitMQ will route the message to all the
-queues in that set. For this plugin to work it is necessary to
-route messages to an exchange that would partition messages, so they
-are routed to _at most_ one queue (a subset).
-
-The plugin provides a new exchange type, `"x-modulus-hash"`, that will use
+RabbitMQ provides a built-in exchange type, `"x-modulus-hash"`, that will use
 a hashing function to partition messages routed to a logical queue
-across a number of regular queues (shards).
+across a number of regular queues (shards). This exchange type is available
+in core RabbitMQ and does not require enabling this plugin to be used.
 
 The `"x-modulus-hash"` exchange will hash the routing key used to
 publish the message and then it will apply a `Hash mod N` to pick the