chore: add Gnss Type known issue

kura/distrib/RELEASE_NOTES.txt

@@ -67,6 +67,7 @@ Target Platform Updates:
 Known Issues:
   * During a wifi scan, some access points with the WPA/WPA2 wifi security are recognized as WPA.
   * On devices with Ubuntu 20.04, the DHCP server provided by isc-dhcp-server may not assign an IP address to the clients. Use dnsmasq instead.
+  * Different GNSS Type retrieved from different Position Providers (see #5409 for details)
   * Snapshot rollback operation may fail processing factory component configurations.
   * The firewall rule applied by the network threat manager that block uncommon TCP MSS values is not applied in the Nvidia Jetson Nano.
   * When the IPv6 network threat manager is disabled, the filtering on TCP fragments is disabled only after a reboot.