wifi: iwlwifi: remove support of versions 4 and 5 of iwl_alive_ntf

These are not used in any of our devices. Remove them.

Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250711183056.dd784443be53.I4ff3b2392294f5df2625a71e2deee3364e9708f6@changeid