builtin: pass repository to sub commands

In 9b1cb5070f (builtin: add a repository parameter for builtin
functions, 2024-09-13) the repository was passed down to all builtin
commands. This allowed the repository to be passed down to lower layers
without depending on the global `the_repository` variable.

Continue this work by also passing down the repository parameter from
the command to sub-commands. This will help pass down the repository to
other subsystems and cleanup usage of global variables like
'the_repository' and 'the_hash_algo'.

Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

parse-options.h

@@ -3,6 +3,8 @@
 
 #include "gettext.h"
 
+struct repository;
+
 /**
  * Refer to Documentation/technical/api-parse-options.txt for the API doc.
  */
@@ -73,7 +75,7 @@ typedef enum parse_opt_result parse_opt_ll_cb(struct parse_opt_ctx_t *ctx,
 					      const char *arg, int unset);
 
 typedef int parse_opt_subcommand_fn(int argc, const char **argv,
-				    const char *prefix);
+				    const char *prefix, struct repository *repo);
 
 /*
  * `type`::