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/BUILD.bazel

@@ -8,6 +8,7 @@ go_library(
         "doc.go",
         "pattern.go",
         "readerfactory.go",
+        "string_array_flag.go",
         "trie.go",
     ],
     importpath = "github.com/grpc-ecosystem/grpc-gateway/v2/utilities",
@@ -16,7 +17,10 @@ go_library(
 go_test(
     name = "utilities_test",
     size = "small",
-    srcs = ["trie_test.go"],
+    srcs = [
+        "string_array_flag_test.go",
+        "trie_test.go",
+    ],
     deps = [":utilities"],
 )
 

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
 	}

vendor/github.com/grpc-ecosystem/grpc-gateway/v2/utilities/string_array_flag.go

@@ -0,0 +1,33 @@
+package utilities
+
+import (
+	"flag"
+	"strings"
+)
+
+// flagInterface is an cut down interface to `flag`
+type flagInterface interface {
+	Var(value flag.Value, name string, usage string)
+}
+
+// StringArrayFlag defines a flag with the specified name and usage string.
+// The return value is the address of a `StringArrayFlags` variable that stores the repeated values of the flag.
+func StringArrayFlag(f flagInterface, name string, usage string) *StringArrayFlags {
+	value := &StringArrayFlags{}
+	f.Var(value, name, usage)
+	return value
+}
+
+// StringArrayFlags is a wrapper of `[]string` to provider an interface for `flag.Var`
+type StringArrayFlags []string
+
+// String returns a string representation of `StringArrayFlags`
+func (i *StringArrayFlags) String() string {
+	return strings.Join(*i, ",")
+}
+
+// Set appends a value to `StringArrayFlags`
+func (i *StringArrayFlags) Set(value string) error {
+	*i = append(*i, value)
+	return nil
+}

vendor/github.com/grpc-ecosystem/grpc-gateway/v2/utilities/trie.go

@@ -40,7 +40,7 @@ func NewDoubleArray(seqs [][]string) *DoubleArray {
 func registerTokens(da *DoubleArray, seqs [][]string) [][]int {
 	var result [][]int
 	for _, seq := range seqs {
-		var encoded []int
+		encoded := make([]int, 0, len(seq))
 		for _, token := range seq {
 			if _, ok := da.Encoding[token]; !ok {
 				da.Encoding[token] = len(da.Encoding)