docs(database): clarify retryable transaction exception

Signed-off-by: memleakd <121398829+memleakd@users.noreply.github.com>

Author: memleakd

system/Database/Exceptions/RetryableTransactionException.php

@@ -13,6 +13,9 @@
 
 namespace CodeIgniter\Database\Exceptions;
 
+/**
+ * Thrown when a transaction failure may succeed if the whole transaction is retried.
+ */
 class RetryableTransactionException extends DatabaseException
 {
 }

user_guide_src/source/changelogs/v4.8.0.rst

@@ -43,7 +43,7 @@ Interface Changes
 **NOTE:** If you've implemented your own classes that implement these interfaces from scratch, you will need to
 update your implementations to include the new methods or method changes to ensure compatibility.
 
-- **Database:** ``CodeIgniter\Database\ConnectionInterface`` now requires the ``afterCommit()``, ``afterRollback()``, ``inTransaction()`` and ``transaction()`` methods.
+- **Database:** ``CodeIgniter\Database\ConnectionInterface`` now requires the ``afterCommit()``, ``afterRollback()``, ``inTransaction()``, and ``transaction()`` methods.
 - **Logging:** ``CodeIgniter\Log\Handlers\HandlerInterface::handle()`` now requires a third parameter ``array $context = []``. Any custom log handler that overrides ``handle()`` - whether implementing ``HandlerInterface`` directly or extending a built-in handler class - must add the parameter to its ``handle()`` method signature.
 - **Security:** The ``SecurityInterface``'s ``verify()`` method now has a native return type of ``static``.