fix(freertos): Limit idle task name length for copy operation

This commit:
- Updates the FreeRTOS kernel prvCreateIdleTasks() function to
limit the length of the IDLE task name before copying it to avoid memory
out-of-bounds warnings.
- Fixes a bug where in the IDLE task name string could be a non
  null-terminated string in SMP configuration.

components/freertos/FreeRTOS-Kernel/idf_changes.md

@@ -203,6 +203,7 @@ List of changes made to Vanilla FreeRTOS V10.5.1 header files to allow for build
 ### tasks.c
 
 - Backported a change where the IDLE tasks are created with the core ID as a suffix in the task name.
+- Backported a change where the IDLE task name copy length is restricted to avoid out-of-bounds copy errors.
 
 ### timers.c