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/web_https.go

@@ -36,6 +36,7 @@ var curveStringMap = map[string]tls.CurveID{
 	"p256":               tls.CurveP256,
 	"p384":               tls.CurveP384,
 	"p521":               tls.CurveP521,
+	"mlkem1024":          tls.MLKEM1024,
 	"x25519mlkem768":     tls.X25519MLKEM768,
 	"secp256r1mlkem768":  tls.SecP256r1MLKEM768,
 	"secp384r1mlkem1024": tls.SecP384r1MLKEM1024,