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`

services/auth/source/oauth2/assert_interface_test.go

@@ -18,4 +18,4 @@ type sourceInterface interface {
 	auth.PasswordAuthenticator
 }
 
-var _ (sourceInterface) = &oauth2.Source{}
+var _ sourceInterface = &oauth2.Source{}

services/auth/source/oauth2/store.go

@@ -94,4 +94,4 @@ func (s *sizeWriter) Write(data []byte) (int, error) {
 	return len(data), nil
 }
 
-var _ (sessions.Store) = &SessionsStore{}
+var _ sessions.Store = &SessionsStore{}