chore: update Go to v1.27 (#39068)

Only made some necessary changes:

1. remove `GOEXPERIMENT`, only use jsonv2
1. `make fmt`
* `SigningKey` and `Signature` were affected due to some bugs in the
toolchain, so rewrote them
1. remove or fix fragile magic numbers and strings
    * the outputs of image/gzip/zlib packages are different
1. update "nolint" comments for the changed lint behaviors
1. add `tls.MLKEM1024`

cmd/hook.go

@@ -752,7 +752,7 @@ func writeFlushPktLine(ctx context.Context, out io.Writer) error {
 func writeDataPktLine(ctx context.Context, out io.Writer, data []byte) error {
 	hexchar := []byte("0123456789abcdef")
 	hex := func(n uint64) byte {
-		return hexchar[(n)&15]
+		return hexchar[n&15]
 	}
 
 	length := uint64(len(data) + 4)