TUN-8052: Update go to 1.21.5

Also update golang.org/x/net and google.golang.org/grpc to fix vulnerabilities,
although cloudflared is using them in a way that is not exposed to those risks

vendor/golang.org/x/sys/windows/svc/mgr/config.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build windows
-// +build windows
 
 package mgr
 

vendor/golang.org/x/sys/windows/svc/mgr/mgr.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build windows
-// +build windows
 
 // Package mgr can be used to manage Windows service programs.
 // It can be used to install and remove them. It can also start,
@@ -17,7 +16,6 @@ import (
 	"unicode/utf16"
 	"unsafe"
 
-	"golang.org/x/sys/internal/unsafeheader"
 	"golang.org/x/sys/windows"
 )
 
@@ -199,12 +197,7 @@ func (m *Mgr) ListServices() ([]string, error) {
 	if servicesReturned == 0 {
 		return nil, nil
 	}
-
-	var services []windows.ENUM_SERVICE_STATUS_PROCESS
-	hdr := (*unsafeheader.Slice)(unsafe.Pointer(&services))
-	hdr.Data = unsafe.Pointer(&buf[0])
-	hdr.Len = int(servicesReturned)
-	hdr.Cap = int(servicesReturned)
+	services := unsafe.Slice((*windows.ENUM_SERVICE_STATUS_PROCESS)(unsafe.Pointer(&buf[0])), int(servicesReturned))
 
 	var names []string
 	for _, s := range services {

vendor/golang.org/x/sys/windows/svc/mgr/recovery.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build windows
-// +build windows
 
 package mgr
 
@@ -13,7 +12,6 @@ import (
 	"time"
 	"unsafe"
 
-	"golang.org/x/sys/internal/unsafeheader"
 	"golang.org/x/sys/windows"
 )
 
@@ -70,12 +68,7 @@ func (s *Service) RecoveryActions() ([]RecoveryAction, error) {
 		return nil, err
 	}
 
-	var actions []windows.SC_ACTION
-	hdr := (*unsafeheader.Slice)(unsafe.Pointer(&actions))
-	hdr.Data = unsafe.Pointer(p.Actions)
-	hdr.Len = int(p.ActionsCount)
-	hdr.Cap = int(p.ActionsCount)
-
+	actions := unsafe.Slice(p.Actions, int(p.ActionsCount))
 	var recoveryActions []RecoveryAction
 	for _, action := range actions {
 		recoveryActions = append(recoveryActions, RecoveryAction{Type: int(action.Type), Delay: time.Duration(action.Delay) * time.Millisecond})

vendor/golang.org/x/sys/windows/svc/mgr/service.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build windows
-// +build windows
 
 package mgr