[ddwrt] update DDWRTNetworkCache.clearAll()

AI code review PR openhab#20505

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Signed-off-by: Lee Ballard <ballle98@gmail.com>

Author: ballle98

bundles/org.openhab.binding.ddwrt/src/main/java/org/openhab/binding/ddwrt/internal/api/DDWRTNetworkCache.java

@@ -374,10 +374,12 @@ public void clearAll() {
         devicesByMac.clear();
         wirelessClientsByMac.clear();
         hostnameToMac.clear();
+        mergedAwayMacs.clear();
         radiosByInterfaceId.clear();
         firewallRulesByRuleId.clear();
         dhcpLeasesByMac.clear();
         dhcpHostnameToMac.clear();
+        listenersByKey.clear();
     }
 
     private static String normalizeMac(String mac) {