GitHub Action CI: Add Go source file format check (#6090)

https://github.com/XTLS/Xray-core/pull/6057#issuecomment-4364819830

And https://github.com/XTLS/Xray-core/pull/6149#issuecomment-4546876261

proxy/vmess/account.go

@@ -1,9 +1,10 @@
 package vmess
 
 import (
-	"google.golang.org/protobuf/proto"
 	"strings"
 
+	"google.golang.org/protobuf/proto"
+
 	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/common/protocol"
 	"github.com/xtls/xray-core/common/uuid"
@@ -30,7 +31,7 @@ func (a *MemoryAccount) Equals(account protocol.Account) bool {
 }
 
 func (a *MemoryAccount) ToProto() proto.Message {
-	var test = ""
+	test := ""
 	if a.AuthenticatedLengthExperiment {
 		test = "AuthenticatedLength|"
 	}

proxy/vmess/inbound/inbound.go

@@ -138,7 +138,8 @@ func New(ctx context.Context, config *Config) (*Handler, error) {
 func (h *Handler) Close() error {
 	return errors.Combine(
 		h.sessionHistory.Close(),
-		common.Close(h.usersByEmail))
+		common.Close(h.usersByEmail),
+	)
 }
 
 // Network implements proxy.Inbound.Network().

proxy/vmess/outbound/command.go

@@ -1,7 +1,6 @@
 package outbound
 
 import (
-
 	"github.com/xtls/xray-core/common/net"
 	"github.com/xtls/xray-core/common/protocol"
 )

proxy/vmess/outbound/outbound.go

@@ -224,9 +224,7 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 	return nil
 }
 
-var (
-	enablePadding = false
-)
+var enablePadding = false
 
 func shouldEnablePadding(s protocol.SecurityType) bool {
 	return enablePadding || s == protocol.SecurityType_AES128_GCM || s == protocol.SecurityType_CHACHA20_POLY1305 || s == protocol.SecurityType_AUTO