[pkg-go] Bug#956299: update gitaly to 12.9.2

[Pirate Praveen]

Package: gitaly
Version: 1.86.0+dfsg1-1
Severity: important
Control: block 956218 by -1

gitaly master branch in salsa was building fine till yesterday. It 
started failing today after golang-google-grpc was updated to 1.27.1 
from 1.22.1

# gitlab.com/gitlab-org/gitaly/internal/rubyserver/balancer
src/gitlab.com/gitlab-org/gitaly/internal/rubyserver/balancer/balancer.go:123:70: 
undefined: resolver.BuildOption
src/gitlab.com/gitlab-org/gitaly/internal/rubyserver/balancer/balancer.go:220:37: 
undefined: resolver.ResolveNowOption