[PATCH v4 2/7] odb/transaction: use pluggable `begin_transaction()`

[Justin Tobler <jltobler@gmail.com>]

Each ODB source is expected to provide an ODB transaction implementation
that should be used when starting a transaction. With d6fc6fe6f8
(odb/source: make `begin_transaction()` function pluggable, 2026-03-05),
the `struct odb_source` now provides a pluggable callback for beginning
transactions. Use the callback provided by the ODB source accordingly.

Signed-off-by: Justin Tobler <jltobler@gmail.com>
---
 odb/transaction.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/odb/transaction.c b/odb/transaction.c
index 9bf3f347dc..592ac84075 100644
--- a/odb/transaction.c
+++ b/odb/transaction.c
@@ -1,5 +1,5 @@
 #include "git-compat-util.h"
-#include "object-file.h"
+#include "odb/source.h"
 #include "odb/transaction.h"
 
 struct odb_transaction *odb_transaction_begin(struct object_database *odb)
@@ -7,7 +7,7 @@ struct odb_transaction *odb_transaction_begin(struct object_database *odb)
 	if (odb->transaction)
 		return NULL;
 
-	odb->transaction = odb_transaction_files_begin(odb->sources);
+	odb_source_begin_transaction(odb->sources, &odb->transaction);
 
 	return odb->transaction;
 }
-- 
2.54.0.105.g59ff4886a5