doc: release: 3.6: Add note on fixed MCUboot erase issue

Adds a note that the shell mcuboot erase command can no
longer erase the MCUboot or application slots

Signed-off-by: Jamie McCrae <[email protected]>

Author: nordicjm

doc/releases/release-notes-3.6.rst

@@ -280,9 +280,12 @@ Libraries / Subsystems
   * Implemented datetime functionality in MCUmgr OS management group, this makes use of the RTC
     driver API.
 
-  * Fixes an issue in MCUmgr console UART input whereby the FIFO would be read outside of an ISR,
+  * Fixed an issue in MCUmgr console UART input whereby the FIFO would be read outside of an ISR,
     which is not supported in the next USB stack.
 
+  * Fixed an issue whereby the ``mcuboot erase`` DFU shell command could be used to erase the
+    MCUboot or currently running application slot.
+
 * File systems
 
 * Modem modules