docs: release-notes: Add note about enabled C2H ACL FC by default

This commit adds a note that C2H ACL FC is now enabled by default.

Signed-off-by: Pavel Vasilyev <pavel.vasilyev@nordicsemi.no>

doc/nrf/releases_and_maturity/releases/release-notes-changelog.rst

@@ -133,6 +133,8 @@ Bluetooth® LE
     * An issue where a flash operation executed on the system workqueue might result in ``-ETIMEDOUT``, if there is an active Bluetooth LE connection.
     * An issue where Bluetooth applications built with the ``nordic-bt-rpc`` snippet (in the :ref:`ble_rpc` configuration) did not work on the nRF54H20 devices due to incorrect memory mapping.
 
+  * Updated the :kconfig:option:`CONFIG_BT_HCI_ACL_FLOW_CONTROL` Kconfig option to be enabled by default to mitigate the risk of potential deadlocks in the Bluetooth Host.
+
 Bluetooth Mesh
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