app: scripts: Update cbor2 version to 5.9.0

cbor2 had a bug due to which we couldn't use it. Older versions worked.
Now that 5.9.0 is released, let's use it.

Signed-off-by: Tommi Rantanen <tommi.rantanen@nordicsemi.no>

Author: trantanen

app/scripts/requirements.txt

@@ -1,3 +1,3 @@
 # This file lists all the dependencies required to run the sm_dfu_host.py script.
 pyserial
-cbor2==5.7.1
+cbor2==5.9.0