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/github.com/grpc-ecosystem/grpc-gateway/v2/utilities/readerfactory.go

@@ -3,13 +3,12 @@ package utilities
 import (
 	"bytes"
 	"io"
-	"io/ioutil"
 )
 
 // IOReaderFactory takes in an io.Reader and returns a function that will allow you to create a new reader that begins
 // at the start of the stream
 func IOReaderFactory(r io.Reader) (func() io.Reader, error) {
-	b, err := ioutil.ReadAll(r)
+	b, err := io.ReadAll(r)
 	if err != nil {
 		return nil, err
 	}