builtin/pack-redundant: remove subcommand with breaking changes

The git-pack-redundant(1) subcommand has been castrated to require
the "--i-still-use-this" option to do anything since 4406522b
(pack-redundant: escalate deprecation warning to an error,
2023-03-23), which appeared in Git 2.41 and was announced for
removal with 53a92c9552 (Documentation/BreakingChanges: announce
removal of git-pack-redundant(1), 2024-09-02). Stop compiling the
subcommand in case the `WITH_BREAKING_CHANGES` build flag is set.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -1278,7 +1278,9 @@ BUILTIN_OBJS += builtin/mv.o
 BUILTIN_OBJS += builtin/name-rev.o
 BUILTIN_OBJS += builtin/notes.o
 BUILTIN_OBJS += builtin/pack-objects.o
+ifndef WITH_BREAKING_CHANGES
 BUILTIN_OBJS += builtin/pack-redundant.o
+endif
 BUILTIN_OBJS += builtin/pack-refs.o
 BUILTIN_OBJS += builtin/patch-id.o
 BUILTIN_OBJS += builtin/prune-packed.o

git.c

@@ -589,7 +589,9 @@ static struct cmd_struct commands[] = {
 	{ "name-rev", cmd_name_rev, RUN_SETUP },
 	{ "notes", cmd_notes, RUN_SETUP },
 	{ "pack-objects", cmd_pack_objects, RUN_SETUP },
+#ifndef WITH_BREAKING_CHANGES
 	{ "pack-redundant", cmd_pack_redundant, RUN_SETUP | NO_PARSEOPT },
+#endif
 	{ "pack-refs", cmd_pack_refs, RUN_SETUP },
 	{ "patch-id", cmd_patch_id, RUN_SETUP_GENTLY | NO_PARSEOPT },
 	{ "pickaxe", cmd_blame, RUN_SETUP },

t/t5323-pack-redundant.sh

@@ -36,6 +36,12 @@ relationship between packs and objects is as follows:
 
 . ./test-lib.sh
 
+if ! test_have_prereq WITHOUT_BREAKING_CHANGES
+then
+	skip_all='skipping git-pack-redundant tests; built with breaking changes'
+	test_done
+fi
+
 main_repo=main.git
 shared_repo=shared.git