package/go: security bump to version 1.18.6

go1.18.6 includes security fixes to the net/http package, as well as bug fixes
to the compiler, the go command, the pprof command, the runtime, and the
crypto/tls, encoding/xml, and net packages.

https://github.com/golang/go/issues?q=milestone%3AGo1.18.6+label%3ACherryPickApproved



Signed-off-by: Christian Stewart <christian@paral.in>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>