Fix Windows lint: handle close error and exclude vendored WFP types from unused

.golangci.yaml

@@ -92,6 +92,9 @@ linters:
       - linters:
           - unused
         path: client/firewall/iptables/rule\.go
+      - linters:
+          - unused
+        path: client/internal/dns/dnsfw/(types|syscall|zsyscall)_windows.*\.go
       - linters:
           - gosec
           - mirror

client/internal/dns/dnsfw/session_windows.go

@@ -66,7 +66,7 @@ func installFilters(cfg installConfig) (session uintptr, err error) {
 
 	base, err := registerBaseObjects(session)
 	if err != nil {
-		fwpmEngineClose0(session)
+		_ = fwpmEngineClose0(session)
 		return 0, fmt.Errorf("register base objects: %w", err)
 	}