[security] Go 1.18.4 and Go 1.17.12 pre-announcement

[Tatiana Bradley]

Hello gophers,

We plan to issue Go 1.18.4 and Go 1.17.12 on Tuesday, July 12.

These minor releases include PRIVATE security fixes to the standard library.

Following our security policy, this is the pre-announcement of those releases.

Thanks,

Tatiana on behalf of the Go team